Montana Child Support Calculator 2026

Step 1 of 8

Case Information

Basic information about the parents and children involved in this child support calculation.

What this calculator does

This free tool walks you through the official Montana child support worksheets step by step — the same ones used by courts and the Child Support Services Division (CSSD). At the end, it gives you an estimated monthly support amount based on both parents' incomes, parenting time, and allowable expenses.

You'll need: recent tax returns or pay stubs for both parents, health insurance costs, and an idea of how many days each child spends with each parent per year.

Nothing you enter is saved — all calculations happen privately in your browser. Use the Save Draft button at the top if you want to come back later.

Based on CSSD Policy 404.1–2 and ARM 37.62.101–148, using tables effective February 1, 2026. This is an estimate only — final amounts are set by a court or CSSD order.

Case Details

Cause / Case Number (if known)

Date of Calculation

Mother's Full Name

Father's Full Name

Children of This Calculation

Enter each child who is the subject of this support calculation — children shared by both parents listed above.

Step 2 of 8

Mother's Income

Enter annual income from all sources. Annualize all entries and round to whole dollars.

💡 Tip: Use the most recent W-2, tax returns, or pay stubs. If income varies, average the last 3 years. Enter $0 if a category doesn't apply.

Mother's Income Sources (Annual)

1a. Wages, salaries, commissionsFrom W-2 or pay stubs

1b. Self-employment net earningsFrom Schedule C/F or K-1

1c. Pensions, Social SecurityFrom SSA year-end statement

1d. Unearned incomeInterest, dividends, royalties

1e. Imputed incomeIf unemployed or underemployed

1f. Earned Income Tax Credit (EITC)From federal tax return

1g. Other taxable incomeRental, S-corp, prizes, etc.

1h. Other non-taxable incomeTax-exempt interest, etc.

Mother's Allowable Deductions (Annual)

These deductions are for other children (not children of this calculation) and legally required payments.

2a. Ordered child support for other childrenPer court/admin order only

2b. Allowance for other children (no order)Children living with this parent

2c. Ordered alimony/spousal support paidPer court order

2d. Health insurance for other childrenPer court/admin order

2e. Federal income taxFrom tax return

2f. State income taxFrom MT state tax return

2g. Social Security (FICA + Medicare)From W-2 boxes 4 + 6

2h. Mandatory retirement contributionsEmployer-required only

2i. Required employment expenseUnion dues, uniforms, tools, etc.

2j. Dependent care for other childrenLess dependent care tax credit

2k. Other deductionsSpecify below

Step 3 of 8

Father's Income

Enter annual income from all sources. Annualize all entries and round to whole dollars.

💡 Tip: Use the most recent W-2, tax returns, or pay stubs. If income varies, average the last 3 years.

Father's Income Sources (Annual)

1a. Wages, salaries, commissionsFrom W-2 or pay stubs

1b. Self-employment net earningsFrom Schedule C/F or K-1

1c. Pensions, Social SecurityFrom SSA year-end statement

1d. Unearned incomeInterest, dividends, royalties

1e. Imputed incomeIf unemployed or underemployed

1f. Earned Income Tax Credit (EITC)From federal tax return

1g. Other taxable incomeRental, S-corp, prizes, etc.

1h. Other non-taxable incomeTax-exempt interest, etc.

Father's Allowable Deductions (Annual)

2a. Ordered child support for other children

2b. Allowance for other children (no order)

2c. Ordered alimony/spousal support paid

2d. Health insurance for other children

2e. Federal income tax

2f. State income tax

2g. Social Security (FICA + Medicare)

2h. Mandatory retirement contributions

2i. Required employment expense

2j. Dependent care for other children

2k. Other deductions

Step 4 of 8

Child Expenses & Supplements

Enter annual expenses for the children of this calculation — combined total from both parents and any third-party custodian.

Supplemental Expenses (Lines 12a–d)

12a. Child care costLess dependent care tax credit

12b. Child health insurance premiumAnnual out-of-pocket cost only

12c. Unreimbursed medical expensesOnly amounts exceeding $250/child/year, recurring

12d. Other expensesSpecify below

Credit for Expenses Paid (Line 23)

Of the total expenses above, how much does each parent actually pay? The two amounts should add up to the total above.

Mother pays (annual)

Father pays (annual)

Step 5 of 8

Parenting Days

Enter the number of days each child spends with each parent per year. Mother's + Father's days must equal 365 for each child.

💡 A "day" is the majority of a 24-hour period (midnight to midnight) in which the child is with or under the control of a parent. When a child is in school or daycare, the primary contact parent counts as having the child.

Days Per Year With Each Parent (Line 25)

Child

Days with Mother

Days with Father

Total

Long-Distance Parenting Adjustment (WS-D)

If either parent travels more than 2,000 miles/year for parenting time, a long-distance adjustment applies. Leave blank if not applicable.

Mother's annual miles driven for parenting

Mother's other transport cost (non-auto)

Father's annual miles driven for parenting

Father's other transport cost (non-auto)

Step 6 of 8

Calculation Review

Review all calculated values from Worksheets A through E. Go back to any step to make corrections.

Step 7 of 8

Preparer Information

Enter the name of the person completing this worksheet and the date prepared (required on WS-A line 28).

Line 28 — Name & Date

Preparer's NamePerson who completed this worksheet

Date Prepared

Step 8 of 8

Download Your Worksheets

Your completed Montana Child Support Guidelines Worksheets are ready to download.

Download Options

Legal Disclaimer

These worksheets were generated using the Montana Child Support Guidelines Calculator, based on CSSD Policy 404.1–2 and ARM 37.62.101–148 (effective February 1, 2026 tables). This is an estimate only. All child support orders must be reviewed and approved by a court or authorized administrative body. Consult a licensed Montana attorney before filing. No data from this session was transmitted to any server.