Use this child maintenance calculator to estimate how much child maintenance the paying parent should pay, using the same rules as the Child Maintenance Service (CMS). It takes into account the paying parent’s income, the number of children, other children they support and how many nights the children stay with them.
Estimated child maintenance
- A week
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- A month
- –
- A year
- –
- CMS rate
- –
In the example, a paying parent with a gross income of £30,000 and one child, with no shared care, pays about £69.04 a week, or £299.18 a month.
How to use the child maintenance calculator
- Enter the paying parent’s gross yearly income, before tax and NI. The CMS takes off pension contributions.
- Choose how many children the maintenance is for.
- Add other children who live with the paying parent, such as a new partner’s children they support.
- Choose the number of nights the children usually stay with the paying parent each year.
- Tick the benefits box if the paying parent gets certain benefits or a State Pension.
How child maintenance is worked out
The CMS turns yearly income into a weekly figure, then applies one of five rates. Full details are in the CMS guide to how child maintenance is worked out.
| Gross weekly income | Rate | What is paid |
|---|---|---|
| Under £7 | Nil | Nothing |
| £7 to £100, or on certain benefits | Flat | £7 a week |
| £100.01 to £199.99 | Reduced | £7 plus a percentage of income over £100 |
| £200 to £800 | Basic | 12% for 1 child, 16% for 2, 19% for 3 or more |
| £800.01 to £3,000 | Basic plus | Basic rate on the first £800, then 9%, 12% or 15% |
Child maintenance examples
| Gross income | 1 child | 2 children | 3+ children |
|---|---|---|---|
| £12,000 | £120 | £160 | £189 |
| £20,000 | £199 | £266 | £316 |
| £30,000 | £299 | £399 | £474 |
| £40,000 | £399 | £532 | £632 |
| £50,000 | £478 | £637 | £762 |
| £70,000 | £628 | £837 | £1,011 |
The figures rise with income, but not in a straight line, because each rate band uses a different percentage. Use the child maintenance calculator with the paying parent’s actual income rather than reading across from the nearest row.
Child maintenance calculator UK: worked example
Jordan earns £45,000 and pays for 2 children. A new partner’s child lives with Jordan, and the 2 children stay with Jordan 120 nights a year. Gross weekly income is £863.01. It is reduced by 11% for the other child, the basic rate for 2 children is 16%, and shared care of 104 to 155 nights takes off two-sevenths. The child maintenance calculator gives £87.78 a week, or £380.38 a month.
Shared care
If the children stay overnight with the paying parent for at least 52 nights a year, the amount is reduced:
| Nights a year | Reduction |
|---|---|
| 52 to 103 | One-seventh |
| 104 to 155 | Two-sevenths |
| 156 to 174 | Three-sevenths |
| 175 or more | Half, plus £7 a week per child |
Family-based arrangements vs the CMS
Parents can agree child maintenance between themselves, with no fees and no forms. The child maintenance calculator gives a fair starting figure. If you cannot agree, you can apply to the CMS. Direct Pay lets parents pay each other once the CMS has worked out the amount; Collect and Pay, where the CMS collects the money, adds collection fees for both parents. You can also use the official GOV.UK child maintenance calculator.
Related calculators
Check what you take home after tax with the monthly take home pay calculator. For help with childcare costs, see the tax free childcare calculator.
Frequently asked questions
How much child maintenance should I pay for one child?
On the basic rate, 12% of gross weekly income. For a £30,000 income that is about £299 a month, before any shared care reduction.
Is child maintenance based on gross or net income?
Gross income, before tax and National Insurance, less pension contributions. The CMS gets the figure from HMRC.
Does the receiving parent’s income count?
No. Only the paying parent’s income affects the amount.
Can child maintenance be changed?
Yes. The CMS reviews the amount each year, and you can report a change if income moves by 25% or more, or the number of children or nights changes.
About this calculator
This child maintenance calculator follows the 2012 scheme rules used by the CMS in England, Scotland and Wales, checked against GOV.UK on 9 November 2026. It does not cover special expenses or variations. Results are estimates; the CMS makes the official calculation.