Child Support Calculator Lab

It depends on your jurisdiction — this child support calculator by state covers all of them. US states use one of three models: (1) income shares (about 40 states) — both parents’ incomes are combined, a basic obligation is read from the state’s schedule, then split pro-rata; (2) percentage of income (Texas, Wisconsin, Mississippi, Nevada, Alaska, North Dakota) — a flat or tiered percentage of the paying parent’s income; (3) the Melson formula (Delaware, Hawaii, Montana) — each parent keeps a self-support reserve, then primary needs and a standard-of-living adjustment are allocated. Looking for a child support calculator Florida families can use? Florida is an income-shares state and this lab embeds its actual published schedule — the figures for Florida are exact per the statute, not representative. Canada uses the federal child support tables (payor’s income × number of children × province). The UK uses the Child Maintenance Service formula (12%/16%/19% of gross weekly income). Pick your mode above — every one of them is a child support calculator based on income.

This child support calculator for Texas uses a percentage of the obligor’s monthly net resources (gross income minus taxes, Social Security, union dues, and the child’s health insurance): 20% for 1 child, 25% for 2, 30% for 3, 35% for 4, and 40% for 5 or more. Example: $5,000 net resources with 1 child = $1,000/month. There is a cap: percentages apply only to the first $11,700 of net resources for orders finalized on or after September 1, 2025 ($9,200 before that date), so the maximum guideline order for 1 child is now $2,340/month. Obligors with net resources under $1,000/month use a lower schedule (15%/20%/25%/30%/35%). If you searched for a child support calculator Texas parents can use for a first estimate, the US State Estimator tab above applies these exact percentages — no signup, no lead-gen form. Source: Texas Family Code §154.125.

This child support calculator for California uses the statewide uniform guideline, CS = K[HN − (H%)(TN)], where HN is the higher earner’s net monthly disposable income, H% is their timeshare, and TN is the combined net income. K depends on the timeshare and on TN via a statutory fraction — for example, with TN = $4,000, K = (1 + H%) × (0.131 + 4,000/42,149). With 1 child, a $4,000 net income and 0% timeshare for the payer, guideline support is about $904/month. Amounts are multiplied by 1.6 for 2 children, 2.0 for 3, and so on. The K-fraction brackets shown here are the version operative since September 1, 2024. Searching for a child support calculator California families can sanity-check against? Enter your HN, TN, and timeshare in the US State Estimator tab — it runs the full §4055 formula. Source: Cal. Family Code §4055.

Percentage-of-income states publish fixed percentages: Wisconsin 17%/25%/29%/31%/34% of the payer’s gross income; Mississippi 14%/20%/22%/24%/26% of adjusted gross income; Alaska 20%/27%/33% (plus 3% per additional child) of adjusted annual income with a $50/month floor; New York 17%/25%/29%/31%/35% of combined parental income up to a $193,000 cap, split pro-rata; Nevada uses tiered marginal rates (e.g. 16% of the first $6,000, 8% of the next $4,000, 4% above $10,000 for one child). The other ~40 states use income-shares schedules (tables, not flat percentages). The US estimator above applies each state’s actual model automatically.

This custody percentage calculator (also called a child custody percentage calculator) divides the number of overnights the child spends with a parent by 365 and multiplies by 100. Example: 183 overnights ÷ 365 = 50.1%. Common patterns: every-other-weekend visitation ≈ 52 overnights ≈ 14.2%; a 2-2-3 rotation or week-on/week-off schedule ≈ 183 overnights ≈ 50.1%. Courts generally describe under 35% as a primary-custody pattern, 35–49% as shared, and around 50% as equal. The custody-time tab above does this math and labels common schedules — and custody percentage is also a direct input to the shared-custody adjustment tab.

In a true 50 50 custody split (also called joint custody or shared custody), support usually does not drop to zero when incomes differ. Most states use an offset (cross-credit): compute each parent’s theoretical obligation, multiply by the other parent’s time share, and the higher earner pays the difference. Example using a $2,123 basic obligation with a $6,000 vs $3,000 income split at 50/50: parent A owes $707.67, parent B owes $353.83, so A pays B $353.83/month. Some states instead multiply the basic obligation by 1.5 for duplicated household costs before offsetting — courts vary, so treat the cross-credit tab as the standard educational estimate and verify with your state’s worksheet.

Canada uses the federal child support tables: the monthly amount depends on the paying parent’s gross annual income (line 15000 of the tax return), the number of children, and the paying parent’s province. Looking for a child support calculator BC parents can use? This lab embeds British Columbia’s real table values — e.g. a BC payor earning $100,000 with one child pays $955/month under the current tables (Ontario: $932/month). New tables took effect October 1, 2025 (the calculator defaults to these); the 2017 tables apply to support periods before that date — e.g. Ontario $100,000/1 child was $910 under the 2017 tables. Amounts above $150,000 use the published base-plus-percentage rule. Source: Federal Child Support Guidelines (SOR/97-175), simplified tables via Justice Canada.

When each parent has the child at least 40% of the time, Canada uses the set-off method (from Contino v. Leonelli-Contino): look up the table amount for each parent’s income, and the higher-income parent pays the difference. Example (Ontario 2025 tables, 1 child): parent A earns $100,000 (table: $932), parent B earns $60,000 (table: $554) — A pays B $378/month. The Canada tab above has a shared-custody toggle that does exactly this. Note the set-off is the starting point; courts can adjust for the increased costs of two households and special expenses.

The Child Maintenance Service applies the Child Support Act 1991 (Schedule 1) as amended by the Child Support Maintenance Calculation Regulations 2012, using the paying parent’s gross weekly income: nil rate below £7/week; flat £7/week up to £100; reduced rate of £7 plus 17%/25%/31% of income between £100–£200 (1/2/3+ children); basic rate of 12%/16%/19% of income from £200–£800; and basic-plus above £800 (12%/16%/19% on the first £800, then 9%/12%/15% on the rest, up to £3,000/week). Example: £500/week with one child = £60/week; £2,000/week with one child = £96 + £108 = £204/week. Income is reduced by 11%/14%/16% for 1/2/3+ other relevant children the payer supports.

Shared-care nights per year reduce the CMS amount per child: 52–103 nights − 1/7, 104–155 nights −2/7, 156–174 nights −3/7, and 175+ nights − 1/2 plus a further £7/week. Example: £600/week with one child gives a £72 basic amount; with 120 shared-care nights the reduction is 2/7, so £72 × 5/7 = £51.43/week. The weekly amount cannot fall below £7 (except flat-rate cases with 52+ shared-care nights, which drop to nil). Enter your nights in the UK tab to see the exact reduction.

Most states charge simple (not compound) interest on each missed monthly installment from its due date. Estimate it as: interest = missed payment × annual rate × (months overdue ÷ 12), summed over all missed payments, with any payments you did make applied to the oldest debt first. Example: $800/month ordered, 6 months missed, no payments, 6% annual rate → $4,800 principal + $84 interest = $4,884. Statutory rates differ: California charges 10% simple per annum, Texas 6% simple per annum — the arrears tab includes these presets plus a custom rate. Always verify your state’s current rate; some states add penalties on top of interest.

It depends on the state or country. Texas, California, Florida, and New York start from net or adjusted income (gross minus taxes and mandatory deductions); Wisconsin, Nevada, Mississippi, and Alaska use gross (or adjusted gross) income; the UK CMS uses gross weekly income from HMRC data; Canada uses gross annual income from the tax return (line 15000). “Gross vs net” is one of the biggest sources of confusion in online estimates — the US estimator above labels which income each state’s model expects, so enter the right figure.

Usually yes — most states add them on top of the basic obligation and split the total pro-rata by income. Example: a $828 basic obligation plus $200/month for the child’s health insurance = $1,028 total; if the payer earns 70% of the combined income, they pay $719.60. California adds mandatory childcare and uninsured medical costs the same way; Delaware’s Melson formula adds childcare, private school, and 75% of health insurance into the primary need. The US estimator has add-on fields for both.

A child support worksheet is the official step-by-step form courts use: incomes → adjustments → guideline table/formula → add-ons → each parent’s share. Every state publishes its own (e.g. Texas’s OAG worksheet, California’s DissoMaster inputs, Florida’s 61.30 worksheet). This lab mirrors that structure — enter the same numbers you would on the worksheet and you get the same guideline result. Use your browser’s print function on any result to keep a worksheet-style summary of your inputs and the estimate for discussion with a lawyer or mediator.

No. Every figure here is an educational estimate based on published guideline formulas and tables — not legal advice, and not a prediction of what a court will order. Judges can deviate for high incomes, special needs, imputed income, and many other factors, and official worksheets and tables change: verify against your state’s current worksheet, the current Federal Child Support Tables (Justice Canada), or GOV.UK’s child maintenance calculator before acting. For decisions that affect your family, consult a licensed family-law attorney in your jurisdiction.

Yes. This tool runs 100% in your browser — every calculation happens on your device with embedded public tables and formulas. Your incomes, children’s details, and results are never sent to any server, there are no accounts, and nothing is stored. You can even disconnect from the internet after the page loads and it keeps working.