Illinois Maintenance Guideline Calculator: duration by length of the marriage
2026 law · reviewed September 7, 2026
| Length of the marriage at filing | Factor | Guideline duration |
|---|---|---|
| Under 5 years | 0.20 | 0.80 years for a 4-year marriage |
| 5 to under 6 years | 0.24 | 1.20 years for a 5-year marriage |
| 6 to under 7 years | 0.28 | 1.68 years for a 6-year marriage |
| 7 to under 8 years | 0.32 | 2.24 years for a 7-year marriage |
| 8 to under 9 years | 0.36 | 2.88 years for an 8-year marriage |
| 9 to under 10 years | 0.40 | 3.60 years for a 9-year marriage |
| 10 to under 11 years | 0.44 | 4.40 years for a 10-year marriage |
| 11 to under 12 years | 0.48 | 5.28 years for an 11-year marriage |
| 12 to under 13 years | 0.52 | 6.24 years for a 12-year marriage |
| 13 to under 14 years | 0.56 | 7.28 years for a 13-year marriage |
| 14 to under 15 years | 0.60 | 8.40 years for a 14-year marriage |
| 15 to under 16 years | 0.64 | 9.60 years for a 15-year marriage |
| 16 to under 17 years | 0.68 | 10.88 years for a 16-year marriage |
| 17 to under 18 years | 0.72 | 12.24 years for a 17-year marriage |
| 18 to under 19 years | 0.76 | 13.68 years for an 18-year marriage |
| 19 to under 20 years | 0.80 | 15.20 years for a 19-year marriage |
| 20 years or more | Court's discretion | A term equal to the marriage, or indefinite |
The duration factors of 750 ILCS 5/504(b-1)(1)(B), applied to the length of the marriage at the time the action was commenced (reviewed September 7, 2026).
Educational only, not investment, tax, or legal advice. Results are hypothetical estimates that vary with each use and over time and are not guaranteed accurate or complete. Using this tool creates no client relationship with Considerate Capital, and the site that linked here is not affiliated with it. By using it you agree to the tool terms.