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.

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.