Child Maintenance Rates
How the CMS rates apply to gross weekly income.
Read guide →
✦ Free UK online calculator
Child Maintenance Calculator UK
Estimate weekly, monthly and yearly child maintenance payments using the published UK Child Maintenance Service calculation rules.
100% free
No sign-up
Instant results
Calculate Your Child Maintenance
Complete the short form to see your personalised estimate.
Step 1 of 4
Your situation
Will you be paying or receiving child maintenance?
We use the paying parent's income to estimate maintenance in either case.
Your answers stay in your browser.
We do not send your income or childcare
details to a server.
What is the paying parent's income?
Use gross income before Income Tax and National Insurance, after pension contributions already deducted from taxable income.
Use the paying parent's income,
not combined household income.
Only enter contributions not already
deducted from the income provided.
Not every benefit triggers the flat rate.
Check the official qualifying-benefits list.
Tell us about the children
These details help calculate the percentage of income used.
Only count other children who qualify
under CMS rules.
For 3 or more children requiring maintenance,
the main percentage band is the same,
but shared-care reductions are assessed
for each child.
How many nights does each child stay with the paying parent?
Enter agreed overnight stays per year for each child, separately.
Equal day-to-day care is not determined
solely by overnight stays; this may need
an official assessment.
If parents disagree about nights or
household arrangements, the official
CMS decision may differ from this estimate.
Your estimate
Estimated child maintenance
Weekly
—
Monthly average
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Yearly
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Indicative estimates only. This website is independent of GOV.UK and the Child Maintenance Service. Check the official calculator .
Simple and transparent
How does our child maintenance calculator work?
Our step-by-step calculator turns published CMS rules into an easy-to-follow estimate.
01
Enter income details
Add the paying parent's gross income and any eligible pension adjustments.
02
Tell us about your children
Choose the number of qualifying children and other children supported.
03
See your estimated payments
Add overnight care arrangements to view a weekly, monthly and yearly breakdown.
Understand your payments
How is child maintenance calculated in the UK?
The Child Maintenance Service normally begins with the paying parent's gross taxable income. It can account for certain pension contributions and other supported children, then apply a rate based on weekly income and the number of children.
Agreed overnight stays can reduce payments. The precise amount depends on the case, and some circumstances need a separate CMS assessment.
- Gross income and eligible adjustments
- Applicable CMS calculation rate
- Number of children receiving maintenance
- Overnight shared-care arrangements
Example: basic rate
16%
For two children
Example: at £600 gross weekly income and no adjustments, maintenance before shared care is £96 per week.
Published CMS bands
UK child maintenance rates explained
The weekly income band determines which method is used to estimate maintenance.
| Gross weekly income | Rate | How it works |
|---|---|---|
| Below £7 | Nil | £0 per week |
| £7–£100 | Flat | Normally £7 per week |
| £100.01–£199.99 | Reduced | £7 plus a percentage of income above £100 |
| £200–£800 | Basic | 12%, 16% or 19%, depending on the number of children |
| £800.01–£3,000 | Basic Plus | Basic rate on first £800; 9%, 12% or 15% on the remainder |
| Above £3,000 | Special consideration | CMS usually limits assessable weekly income to £3,000; court application may be possible |
Qualifying benefits, other supported children and special circumstances can change the result. Source: GOV.UK detailed CMS guide .
Shared care
How do overnight stays affect child maintenance?
Shared care may reduce maintenance if a child regularly stays overnight with the paying parent.
| Overnight stays per year | Typical reduction per child |
|---|---|
| 0–51 | No reduction |
| 52–103 | 1/7 of that child's amount |
| 104–155 | 2/7 of that child's amount |
| 156–174 | 3/7 of that child's amount |
| 175 or more | 50% of that child's amount, plus £7 per week |
Some flat-rate cases and equal day-to-day care arrangements operate differently. Official shared-care guidance .
Useful resources
Explore child maintenance guides
Understand the rules, payment arrangements and common situations before making decisions.
Overnight Stays & Maintenance
Learn how shared care affects estimated payments.
Read guide →Self-Employed Parent Guide
Find out how self-employment income may be treated.
Read guide →
Your questions answered
Frequently asked questions
Is this child maintenance calculator free?
Yes. This independent calculator is free to use and does not require registration.
Does child maintenance use gross or net income?
CMS generally starts with gross taxable income before Income Tax and National Insurance, after qualifying pension contributions. The official assessment may also take other circumstances into account.
How much maintenance is paid for two children?
For ordinary basic-rate cases with gross weekly income between £200 and £800, the starting amount is generally 16% of adjusted gross weekly income before shared care.
Does shared care reduce child maintenance?
Agreed overnight stays can reduce payments from 52 nights per year. The amount depends on the applicable care band and particular case.
Is the result legally binding?
No. It is only an estimate. The Child Maintenance Service decides any official calculation based on the circumstances and information available to it.
Can I use this if I receive benefits?
Some specified benefits may trigger a flat-rate calculation. Since eligibility and exceptions matter, this tool flags such cases and links to the official CMS calculator.
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Understand your estimated payments today
Free to use, no sign-up, and based on published CMS rules.