Child maintenance: calculators and guides

Written by James Whitfield · Last reviewed 29 October 2026 · Independent, not GOV.UK

Under the Child Maintenance Service rules the paying parent usually pays 12% of gross weekly income for one child, 16% for two or 19% for three or more, on income from £200 to £800 a week. On £600 a week that is £72 for one child or £96 for two, less any overnight stays. Child maintenance you receive does not reduce Universal Credit.

Work out what you might pay or receive

Child maintenance calculatorIncome, children, overnight stays, other children and fees, with every step shown. Shared-care nights calculatorTurn a weekly or fortnightly pattern into nights a year and the CMS band. CMS rates explainedEvery band and percentage, with worked examples and the Collect and Pay fees.

Shared care and different family set-ups

Other children at homeHow the 11%, 14% and 16% income cuts work. Overnight stays52, 104, 156 and 175-night bands, and why equal care is not automatically nil.

Child maintenance and benefits

Child maintenance and Universal CreditReceiving it does not reduce UC; paying it on UC with no earnings is £7 a week. Benefits after separationChild Benefit, Universal Credit, Council Tax and childcare: a checklist. Single parent benefits calculatorWhat you could get on your own. Child Benefit calculator£27.05 a week for the eldest child, £17.90 for each other child (2026/27).

The rates at a glance

Gross weekly income	Rate
Under £7	Nil
£7 to £100, or a qualifying benefit	£7 a week (flat rate)
£100.01 to £199.99	£7 plus 17%, 25% or 31% of income over £100
£200 to £800	12%, 16% or 19%
£800.01 to £3,000	Basic on £800, then 9%, 12% or 15%

Payments, fees and records

Collect and Pay fees20% added for the paying parent, 4% off for the receiving parent, against Direct Pay. Income change checkerIs the change 25% or more? What it does to the amount. Arrears trackerWhat was due against what arrived, with a printable record. Nothing is saved. Separation budgetMonthly money in and out after separating, with Child Benefit filled in.

Changes, missed payments and disagreements

Report changes to the CMS, which reviews each case's income once a year. You can ask it to look at a decision again (mandatory reconsideration) within one month. If you do not feel safe dealing with the other parent, you do not have to arrange anything directly: the CMS can collect and pass on payments. GOV.UK: report a change · GOV.UK: payments and fees

Want it all in writing?

The Child Maintenance Pack is an 18-page workbook: the 2026/27 rates, your figure step by step, a shared-care diary, an arrangement template you can both sign and a payment record. £4.99, one-off. The calculators here stay free.

See the Child Maintenance Pack

Sources: Child Support Act 1991, Schedule 1; Child Support Maintenance Calculation Regulations 2012; DWP "How we work out child maintenance" (updated 1 April 2026); GOV.UK. Checked 29 October 2026. This site is independent of the government and the Child Maintenance Service.