UK Child Maintenance Calculator (2026)
Enter gross weekly income, the number of qualifying children, any other children in the paying parent's household, and shared-care overnights to see an estimated weekly and monthly child maintenance figure, with the full step-by-step working shown. Free, instant, and calculated entirely in your browser; no email or phone number required.
Estimated Child Maintenance
£96.00 /week
Basic rate · estimate only, not a CMS decision
Per week
£96.00
Per month
£416.00
This tool estimates the CMS 2012 scheme gross-income formula only: nil rate below £7/week, a flat £7/week from £7 to £100, a reduced rate from £100.01 to £199.99, a basic rate from £200 to £800, and a basic plus rate from £800.01 up to the £3,000 income ceiling. It does not check eligibility, verify income, or apply variations. The Child Maintenance Service makes the binding calculation from verified income and full case details.
How Child Maintenance Is Calculated
Child maintenance under the Child Maintenance Service's (CMS) 2012 scheme is worked out from the paying parent's gross weekly income, using a set of published income bands and percentage rates:
- Nil rate: gross weekly income below £7.00
- Flat rate: £7.00 to £100.00 a week, a fixed £7.00 regardless of income within the band
- Reduced rate: £100.01 to £199.99 a week
- Basic rate: £200.00 to £800.00 a week
- Basic plus rate: £800.01 up to the £3,000.00 income ceiling
The percentage used within the reduced, basic, and basic plus bands depends on how many qualifying children the maintenance is for (one, two, or three or more). If the paying parent has other children living in their own household, gross income is reduced by 11%, 14%, or 16% (for one, two, or three or more other children) before the basic or basic plus rate is applied; this reduction does not apply to the flat or reduced rate bands.
Finally, if the children stay overnight with the paying parent, the weekly amount is reduced for shared care: by one-seventh for 52 to 103 nights a year, two-sevenths for 104 to 155 nights, three-sevenths for 156 to 174 nights, and by half plus a further £7.00 a week for 175 nights or more. Income above £3,000.00 a week is not used in the formula, though a court can sometimes order an additional "top-up" amount above that ceiling.
The official explanation of this formula is published at gov.uk: How child maintenance is worked out. See the full child maintenance guide for how to apply, how payments are collected, and what happens if a parent stops paying, and how much child maintenance for worked examples at different income levels.
Who Has To Pay
Child maintenance is normally payable by the parent who does not have day-to-day (main) care of a child, to the parent or person who does, until the child turns 16 (or 20 if still in full-time non-advanced education). Either parent can apply to the Child Maintenance Service, or parents can arrange payments privately between themselves without involving the CMS. This tool does not check who is eligible to apply or receive maintenance; it only calculates the amount the statutory formula would produce from the figures you enter.
Frequently Asked Questions
How accurate is this child maintenance calculator?
It applies the published CMS 2012 scheme gross-income formula exactly. It is still an estimate: the Child Maintenance Service verifies income (usually with HMRC data), checks for other children and shared care in detail, and can apply variations for things like additional income or expenses that this calculator does not model.
What counts as gross weekly income for child maintenance?
Broadly, it is income before tax and National Insurance, but after deducting pension contributions, from employment, self-employment, and some other regular income sources. The CMS normally gets this figure from HMRC records for the most recent tax year.
Does shared custody reduce child maintenance?
Yes. Overnight stays with the paying parent reduce the weekly amount: by one-seventh for 52 to 103 nights a year, rising to a half plus a further £7 deduction for 175 nights or more. If care is genuinely equal, no maintenance is normally payable at all, though this is decided case by case.
Do other children in the paying parent’s household reduce the amount?
Yes, but only within the basic and basic plus rate bands (gross weekly income of £200 or more). Gross income is reduced by 11% for one other child, 14% for two, or 16% for three or more, before the rate is applied. This does not apply to the flat or reduced rate bands.
What is the maximum child maintenance someone can be asked to pay?
The statutory formula only uses gross weekly income up to £3,000; income above that is ignored by the CMS calculation. A parent receiving maintenance can sometimes apply to a court for an additional "top-up" order if the paying parent earns more than that.
Does this tool store or send my information anywhere?
No. All of the math runs in your browser. Nothing you type into this calculator is saved, transmitted, or used to contact you.
This calculator estimates the CMS 2012 scheme gross-income formula published at gov.uk. It is general information, not legal or financial advice, and RecordingLaw.com is not affiliated with the Child Maintenance Service or the UK government. The figure shown is an estimate only; the Child Maintenance Service makes the binding calculation for any actual case, based on verified income and full case details.
Know someone who could use this? Share this free tool: