Child Maintenance Calculator

What Is a Child Maintenance Calculator?

A child maintenance calculator UK estimates the weekly amount a paying parent may need to provide when a child mainly lives with the other parent. It follows the standard Child Maintenance Service approach using gross weekly income, the number of qualifying children, other children supported and overnight shared care.

You may also see this type of tool described as a child maintenance service calculator, child maintenance online calculator, monthly child maintenance calculator or maintenance payment calculator UK. The result is an estimate rather than a binding CMS assessment.

Parents asking how much child maintenance should I pay or how much child maintenance should I receive can use it for budgeting or discussing a private arrangement. Find other tools at Childcare Calculator UK.

How to Use the Child Maintenance Calculator

Enter the Paying Parent’s Gross Weekly Income

Enter the weekly income CMS would normally use after eligible occupational or personal pension contributions. Do not enter take-home pay after Income Tax and National Insurance.

CMS usually obtains annual income from HMRC and converts it into a weekly figure. The standard formula is capped at £3,000 per week; a court may consider additional maintenance above that level.

Enter the Children Requiring Maintenance

Enter how many qualifying children are covered by this calculation. Although the field accepts up to 20, the percentage bands use three groups: one child, two children, or three or more children.

It differs from the complete cost of bringing up a child, explored with the Cost of Raising a Child Calculator UK.

Add Other Children the Paying Parent Supports

Enter other children taken into account under CMS rules. Leave the field blank when there are none.

From £200, it reduces income by 11% for one other child, 14% for two, or 16% for three or more. The Reduced rate uses separate percentages.

Enter Shared-Care Nights

Enter the number of overnight stays per year for each qualifying child. This calculator applies the same number of nights to every child in the calculation.

The standard reductions are:

• Fewer than 52 nights: no reduction
• 52 to 103 nights: one-seventh
• 104 to 155 nights: two-sevenths
• 156 to 174 nights: three-sevenths
• 175 or more nights: 50%, followed by an additional £7 reduction for each child

The amount cannot fall below £7 after the normal shared-care adjustment. Select equal day-to-day care separately; the calculator then shows no CMS liability.

A Child Care Hours calculator may organise schedules, but CMS shared care concerns overnight stays and day-to-day care.

Select Benefits and Payment Method

Choose “Yes” when the paying parent receives a listed flat-rate benefit. The calculator applies £7 weekly, subject to shared care.

Direct Pay applies no collection fees. Collect and Pay adds 20% for the paying parent and deducts 4% from the receiving parent.

How Is Child Maintenance Calculated?

The applicable child maintenance brackets depend on adjusted gross weekly income:

• Below £7: Nil rate
• £7 to £100, or a listed benefit: Flat rate of £7
• More than £100 but below £200: Reduced rate
• £200 to £800: Basic rate
• More than £800 up to £3,000: Basic Plus rate

At the Basic rate, the calculator uses:

• 12% for one qualifying child
• 16% for two qualifying children
• 19% for three or more qualifying children

At the Basic Plus rate, those percentages apply to the first £800. Income above £800 uses 9% for one child, 12% for two or 15% for three or more.

The Reduced rate starts with £7 and adds a percentage of income above £100, based on qualifying and other supported children.

This explains how is child maintenance calculated and why there is no single average child maintenance UK amount that suits every family.

Worked Child Maintenance Example

Assume the paying parent enters:

• Gross weekly income: £600
• Qualifying children: 2
• Other children supported: 1
• Shared-care nights per child: 104
• Listed flat-rate benefit: No
• Equal day-to-day care: No
• Payment method: Direct Pay

The calculator first adjusts income for one other supported child:

£600 × 89% = £534 adjusted weekly income

Two qualifying children use the 16% Basic rate:

£534 × 16% = £85.44 before shared care

For 104 nights, the calculator applies a two-sevenths reduction:

£85.44 × 2 ÷ 7 = £24.41 reduction

Estimated weekly maintenance:

£85.44 − £24.41 = £61.03

The calculator then displays:

• Estimated Weekly Maintenance: £61.03
• Average Monthly Maintenance: £264.46
• Annual Maintenance: £3,173.49
• Income Used After Adjustment: £534.00
• CMS Rate Band: Basic
• Before Shared Care: £85.44
• Shared-care Reduction: £24.41
• Paying Parent Weekly Total: £61.03
• Receiving Parent Weekly Amount: £61.03

Monthly maintenance is weekly maintenance multiplied by 52 and divided by 12. Annual maintenance is the weekly figure multiplied by 52. The calculator retains unrounded values before formatting.

What Can Change the Estimate?

The CMS decision can differ because of HMRC income, pensions, benefits, child-specific shared care, variations or allowable expenses.

A child maintenance variation calculator may illustrate changed circumstances, but this tool does not assess formal variations.

The phrase UK child maintenance calculator 2025 still appears in searches, but current rules should be used. The CMS framework covers England, Wales and Scotland, so a child maintenance calculator Scotland should not invent different percentages.

Northern Ireland users may search for a child maintenance Ireland calculator, but should check the relevant official service. The Republic of Ireland uses a different legal system.

Child Benefit is separate from maintenance. Parents planning the benefit received for eligible children should use the Child Benefit Calculator UK.

FAQs

Q1: How much child maintenance per week will I pay?
A: It depends on adjusted gross weekly income, qualifying children, other children supported, benefits and shared-care nights.

Q2: How much is child maintenance for two children?
A: At the Basic rate, the starting amount is 16% of adjusted gross weekly income before any shared-care reduction.

Q3: Is the calculator legally binding?
A: No. It provides an indicative estimate. Check the official GOV.UK calculator for what the government is likely to work out.

Q4: Does this maintenance calculator UK cover every CMS case?
A: No. It does not fully assess variations, multiple receiving households, disputed income or a different number of overnight stays for each child.