Illinois Divorce
Cost Estimator

The court filing fee for divorce in Illinois is $289–$388 — above the national median ($184 national median). Total out-of-pocket costs depend heavily on whether the case is contested or uncontested, whether children are involved, and how complex the financial issues are.

An uncontested divorce may cost as little as $289–$388 plus a few hundred for paperwork; a fully contested case with custody disputes varies significantly — use the calculator above for a Illinois-specific estimate.

Filing fees in Illinois vary by county — the range reflects differences between local court fee schedules. Beyond the filing fee, budget for service of process ($50–$150), a response fee if your spouse files an answer, mandatory parenting classes if minor children are involved, and potential mediation or family law attorney fees.

For a full breakdown of Illinois court costs, see the Illinois Court Filing Fees guide. This Illinois divorce cost calculator helps you project realistic total divorce costs for the dissolution of marriage process in 2026.

Total divorce costs in Illinois include alimony or spousal support obligations (use the Illinois alimony calculator for a separate estimate), child support if minor children are involved (use the Illinois child support calculator), and family law attorney fees for the divorce process from petition through final decree. Illinois family law governs the dissolution of marriage, division of marital property, alimony, and child support — speak with a Illinois family law attorney before relying on this divorce cost calculator output for any legal decision.

Illinois became a purely no-fault divorce state in 2016 when the legislature eliminated fault-based grounds entirely under 750 ILCS 5/401(a). The 6-month separation period creates an irrebuttable presumption of irreconcilable differences — but courts may waive it if both spouses agree in writing.

Spousal maintenance in Illinois (the term Illinois family law uses instead of alimony) is calculated using a statutory formula under 750 ILCS 5/504. The Illinois spousal maintenance calculator formula takes 33.3% of the payor's net income minus 25% of the payee's net income, capped at 40% of the parties' combined net income.

Duration of spousal support in Illinois is tied to the length of the marriage — for a 10-year marriage, maintenance runs 4.4 years (0.44 multiplier per 750 ILCS 5/504(b-1)(1)). Illinois gross income and net income are both used in different parts of the divorce financial calculation: gross income is used for child support guideline calculations, while net income is used for the spousal maintenance formula.

An Illinois divorce cost calculator can estimate total costs including family law attorney fees, court filing fees, and the potential monthly spousal maintenance obligation. Illinois courts calculate spousal maintenance (the Illinois term for alimony) under 750 ILCS 5/504 using gross income: the maintenance amount equals 33.3% of the payor's net income minus 25% of the payee's net income, capped at 40% of combined net income.

The length of the marriage determines the duration: maintenance lasts 20% of the marriage length for marriages under 5 years, scaling up to permanent maintenance for marriages over 20 years. The Illinois Marriage and Dissolution of Marriage Act governs all aspects of divorce — child custody, child support amounts, maintenance, and marital property division.

Mediation is commonly used for contested Illinois divorces, and a legal advice consultation with a family law attorney helps clarify expected divorce costs before the divorce process begins.

The court filing fee to initiate a divorce in Illinois is $289–$388. Fees vary by county within the state.

This fee is paid when you file the petition with the court and is not reimbursable. Illinois filing fees are set county-by-county under 705 ILCS 105/27.1a–27.2, so Cook County fees ($388+) differ substantially from rural downstate counties ($100–$150).

Schedule a consultation with an Illinois divorce lawyer to discuss your case and understand total costs.

If you cannot afford the filing fee, most Illinois courts allow you to file a fee waiver petition (sometimes called an "in forma pauperis" application). You will need to demonstrate financial hardship, typically by showing income below 150% of the federal poverty level — see the HHS federal poverty guidelines for current thresholds.

An uncontested divorce in Illinois — where both spouses agree on all issues — is dramatically cheaper. Total costs typically include filing fees plus minimal attorney involvement for document review.

A contested divorce, where spouses disagree on custody, property division, or support, can run into five figures per side depending on Illinois court costs, attorney fees, and dispute complexity. Each court appearance, discovery request, and motion adds to the total.

High-conflict cases in major metro areas frequently exceed $50,000 per side. The longer the case takes, the higher the cost — most contested divorces in Illinois take 6–18 months to resolve.

Many cases start contested and settle before trial. According to NCSC court data, approximately 95% of divorce cases reach settlement before trial.

Mediation can accelerate this process and significantly reduce costs. If your divorce involves children or spousal support, also use the Illinois Child Support Estimator and the Illinois Alimony Calculator to project those costs alongside attorney fees.

Contested divorces in Illinois average 12–18 months to resolve in Cook County, where the divorce process commonly stretches trial dates 6+ months. Cases involving business valuations, maintenance calculations, or alimony in Illinois commonly exceed $40,000 per side in Cook, DuPage, and Lake counties.

The child support amount in Illinois is calculated separately under the Income Shares model and the Illinois child support guidelines. Illinois spousal support calculator tools can estimate maintenance, but courts retain discretion in alimony payments and duration of alimony based on 14 statutory factors.

Mediation is one of the most effective ways to reduce divorce costs in Illinois. A neutral mediator helps both spouses negotiate custody, support, and property division.

Mediation in Illinois generally costs a fraction of litigation — costs depend on the mediator's rate, number of sessions, and complexity of disputes. Before mediation, use the Illinois Property Division Calculator to understand how assets may be split under Illinois law.

Some Illinois courts require mediation before allowing a contested case to proceed to trial. Even voluntary mediation can save thousands in attorney fees and months of court time.

Collaborative divorce — where each spouse has their own attorney but everyone commits to settling without litigation — is another cost-effective alternative. According to NCSC national divorce data, cases that reach mediation settle at significantly higher rates than those that proceed directly to contested hearings.

Illinois spousal maintenance (the Illinois term for alimony) is calculated under 750 ILCS 5/504 using a statutory formula: 33.3% of the payor's net income minus 25% of the payee's net income, capped at 40% of the parties' combined net income. This formula applies when the parties' combined gross income is $500,000 or less per year — above that threshold, Illinois courts use the 14 statutory factors and discretion rather than the formula.

Maintenance calculations in Illinois always use net income (after taxes and mandatory deductions), not gross income. Illinois spousal maintenance is separate from child support, which uses gross income under the Illinois child support guidelines.

Duration of alimony in Illinois depends entirely on the length of the marriage. For a marriage under 5 years, maintenance lasts 20% of the marriage length.

The multiplier increases with marriage length — a 10-year marriage yields 4.4 years of Illinois spousal maintenance (0.44 multiplier); a 15-year marriage yields 9.6 years (0.64 multiplier); marriages over 20 years may result in permanent maintenance. An Illinois alimony calculator or Illinois spousal maintenance calculator applies these multipliers automatically once you input each spouse's net income and the marriage length.

The Illinois Marriage and Dissolution of Marriage Act governs all maintenance in Illinois — consult an Illinois family law attorney for case-specific legal advice on spousal maintenance payments and whether the formula applies to your divorce.

An Illinois alimony calculator estimates spousal support by applying the 750 ILCS 5/504 formula to both spouses' net income — the output is a monthly maintenance amount and a projected duration based on marriage length. The Illinois spousal support calculator is particularly useful during Illinois divorce negotiations because the formula produces a defined number that both parties can use as a baseline.

Alimony payments in Illinois are modifiable if a substantial change in circumstances occurs — a significant income increase by the recipient or income loss by the payor can justify modification. Unlike child support (which uses gross income under Illinois child support guidelines), Illinois maintenance uses net income after taxes.

A spousal support calculator for Illinois must account for both the monthly payment amount and the duration multiplier — both are formula-driven, making the Illinois maintenance calculation more predictable than in states that rely on judicial discretion alone. Illinois divorce costs increase substantially when alimony is contested — spousal support disputes in Cook, DuPage, and Lake counties regularly add $15,000–$40,000 to total divorce costs.

The Illinois alimony calculator above provides an estimate for planning purposes; actual maintenance awards require a court order under the Illinois Marriage and Dissolution of Marriage Act.

Illinois maintenance calculations follow the statutory formula under 750 ILCS 5/504 — the foundation of every maintenance in Illinois determination. The Illinois alimony calculator applies this formula to both spouses' net income and the length of the marriage to produce an estimated monthly maintenance amount and projected duration.

Illinois family law practitioners — including alimony attorneys in Cook, DuPage, and Lake counties — use the same formula as the starting point for settlement negotiations. Illinois maintenance is distinct from Illinois child support: maintenance calculations use net income while child support uses gross income.

An Illinois divorce cost calculator estimates maintenance alongside attorney fees and filing costs so divorcing spouses can plan financially before retaining legal counsel. Illinois family law courts apply the 14 statutory factors under 750 ILCS 5/504(a) when combined income exceeds $500,000 — for most cases, the formula controls.

Consulting experienced alimony attorneys in Illinois is strongly recommended when maintenance is likely to be contested.

A Illinois divorce cost calculator works best when each input maps to a real divorce cost line item. Start with the $289–$388 Illinois family court filing fee, then layer in service on your spouse, response fees, parenting classes, divorce mediation sessions, the divorce attorney retainer, custody evaluation fees, appraisals on marital assets, business valuations for equitable distribution, and expert witnesses.

The split between an uncontested divorce and a contested divorce in Illinois is rarely the filing fee — it is the divorce attorney hours spent in family court resolving custody, child support, alimony, and spousal support.

For an uncontested divorce in Illinois, the calculator should ask whether both spouses agree on equitable distribution of marital assets, debt allocation, parenting time, child support, alimony, and spousal support before estimating attorney fees. A flat-fee divorce lawyer or limited-scope divorce attorney may be enough when every term between the spouses is settled.

If either spouse disputes custody, income, separate property, business value, retirement accounts, alimony, or spousal support, the contested divorce path triggers hourly divorce attorney billing, additional divorce mediation, more family court appearances, and a longer divorce process before the divorce decree is entered.

The strongest Illinois divorce cost estimate uses actual documents at the divorce attorney consultation: the Illinois court fee schedule, pay stubs and tax returns for each spouse, mortgage statements, bank and retirement account balances for the marital assets, credit card debt, business records, and a proposed parenting schedule. Those inputs let the divorce cost calculator project divorce attorney fees, divorce mediation costs, and ongoing exposure from child support, alimony, and spousal support.

If your Illinois divorce involves children, pair the divorce cost calculator with the Illinois child support calculator and custody time calculator so the family court budget reflects the full divorce process — not just the filing fee or the divorce attorney retainer.

A Illinois divorce lawyer cost worksheet should separate the divorce attorney retainer from the total attorney fees likely to be billed across the divorce process. At the consultation, ask whether the divorce lawyer charges a flat fee for uncontested divorce, an hourly rate for contested divorce in Illinois family court, a replenishing retainer, separate appearance fees, or extra charges for discovery, divorce mediation, custody disputes, business valuation, retirement division, alimony or spousal support hearings, and trial preparation.

The same divorce attorney may quote three very different divorce cost ranges depending on which path the spouses choose.

The fastest way to reduce divorce cost in Illinois is to identify which issues are actually contested between the spouses. Equitable distribution of marital assets, child custody, parenting time, child support, alimony, spousal support, separate property claims, hidden income, business interests, and real estate disputes drive divorce attorney hours in family court.

When those issues are settled before filing — often through divorce mediation with a neutral mediator — the divorce cost calculator can use the uncontested divorce or limited-scope divorce attorney path rather than a full contested divorce litigation budget, and the divorce decree can be entered far sooner.

Before the first divorce attorney consultation, bring a one-page divorce cost worksheet covering each spouse's income, marital assets, debts, children, requested parenting schedule, known disputes, filing county in Illinois, and any deadline pressure. That worksheet lets the divorce lawyer quote a realistic divorce cost range instead of a generic retainer, and it gives the spouses a cleaner comparison between divorce mediation, collaborative divorce, flat-fee document review by a Illinois divorce attorney, and full divorce attorney representation through family court to the final divorce decree.

A illinois divorce cost calculator should estimate more than the court filing fee. The real total usually combines petition filing fees, service of process, answer or response fees, mediation, parenting education, document preparation, attorney consultation, hourly legal fees, expert witnesses, custody evaluations, appraisals, and the cost of preparing a final divorce decree.

For an uncontested divorce, the major variables are the filing fee, whether both spouses sign a settlement agreement, and whether a flat-fee attorney reviews the paperwork. For a contested divorce, the cost estimate should assume discovery, court appearances, negotiations over child custody and child support, alimony or spousal support analysis, property division, and attorney fees that increase with every unresolved issue.

Use the calculator before choosing between self-help forms, online divorce paperwork, mediation, limited-scope representation, and full legal representation. A low-cost divorce path only works when both spouses agree on the divorce process, assets, debts, parenting time, and support.

If those issues are disputed, a Illinois divorce lawyer cost estimate should include a retainer and enough hourly attorney time to reach settlement or prepare for trial.

Divorce attorney fees and legal fees in Illinois vary by experience, location, and case complexity. The divorce process typically requires legal representation for contested matters — especially child custody disputes, business valuations, and spousal support hearings.

Hourly rates and retainers vary widely by market; request quotes from multiple attorneys and compare flat-fee vs. hourly structures.

Many Illinois attorneys offer a free or low-cost initial consultation to assess your case before committing to legal services.

You can reduce attorney costs by organizing your financial documents before the first meeting, communicating with your spouse directly on uncontested issues, and using the attorney for legal advice rather than emotional support. A worksheet listing your assets, debts, income sources, and monthly expenses helps your attorney work efficiently and reduces billable time spent on discovery.

Divorce attorney fees are the largest single line item for most Illinois cases. A divorce attorney consultation typically runs $0 to $400 depending on the firm, and hourly rates fall between $200 and $500+ in most metro markets — higher in major cities, lower in rural counties.

A typical Illinois divorce attorney requires a retainer of $3,000 to $10,000 up front, replenished as the case progresses. A divorce calculator should always separate the retainer from the projected total — the retainer is a deposit, not a cap.

Court costs in Illinois start with the $289–$388 filing fee, plus service of process ($50–$150), response fees, and mandatory parenting classes when minor children are involved. The Illinois divorce process moves through petition, response, discovery, temporary orders, mediation, and either settlement or trial — each stage has its own fee structure.

Mediation with a private mediator costs far less than full litigation in family law court, which is why most Illinois judges require at least one mediation session before scheduling a contested hearing.

Total divorce cost in Illinois depends almost entirely on whether the case is contested. An uncontested divorce in Illinois — where both spouses agree on equitable distribution of marital assets, alimony or spousal support, and child support — typically lands between $1,500 and $5,000 all-in.

A contested divorce with disputed custody, business valuation, or hidden assets runs $15,000 to $50,000+ per spouse. Run the alimony calculator and child support estimator alongside this divorce calculator so the projected total includes ongoing support obligations, not just the one-time legal fees.

A Illinois divorce lawyer typically charges a retainer fee upfront, then bills against it at an hourly rate. Hourly billing for a divorce attorney in Illinois commonly runs $250–$500/hour, with retainers of $2,500–$10,000 depending on complexity.

A flat-fee uncontested divorce — when both spouses agree on all terms — often costs $500–$2,500 total, while a contested divorce filing in Illinois family court can run $15,000–$40,000 per spouse before trial.

Contested divorce settlement in Illinois involves alimony (spousal support) negotiations, child custody disputes, and marital property division — each adds attorney hours. Uncontested divorce skips those battles: spouses agree on custody, support, and property, file a joint petition, and wait for the divorce decree.

Divorce mediation is the middle path — a neutral mediator helps the couple reach a settlement, often saving 50–70% versus litigation in Illinois family court. The mediated agreement still becomes part of the final divorce decree.

Hidden costs surface in contested Illinois divorce cases: court reporter fees for depositions ($500–$2,000 each), expert witness fees for forensic accountants ($5,000–$25,000) when business valuations or hidden assets are at issue, and child psychologists ($2,500–$10,000) for contested custody evaluations. A Illinois divorce filing also carries supplemental costs — process server fees, certified copies of the divorce decree, parenting class fees, and QDRO preparation for retirement account division.

See 755 ILCS 5/27-2 for procedural rules.