Paycheck calculator › API
paysums API: paycheck, tax, mortgage and sales-tax calculations as JSON (2026)
The same engines and tables behind every page on this site, over HTTPS. One GET returns a full paycheck breakdown for any US state (with city taxes), the UK, Canada, Australia, Germany, France or India; other endpoints solve the salary needed for a target take-home, price a mortgage with this week's rate, look up sales tax by ZIP, and hand you the raw 2026 tables. No SDK, no sign-up for the free tier, CORS enabled, tables refreshed automatically.
Quick start
curl 'https://paysums.com/api/v1/paycheck?country=US&state=CA&amount=90000&period=annual&filing=single&k401Pct=6'Returns gross, net, taxes, effective, marginal, per-period amounts (periods.monthly, biweekly, weekly, hourly…) and an items array with every tax line and a one-sentence how explaining it — e.g. "Taxable income $73,900 = wages $90,000 − standard deduction $16,100, through the 2026 brackets". POST the same fields as JSON ({"country":"US","input":{…}}) if you prefer.
GET /api/v1/paycheck
| Parameter | Values |
|---|---|
country | US (default), UK, CA, AU, IN, DE, FR |
amount, period | gross pay and its period: annual, monthly, semimonthly, biweekly, weekly, daily, hourly (+ hours per week) |
| US | state (2-letter, or DC), filing = single | married | head, local (city key such as nyc, philadelphia), k401Pct, k401, hsa, health, dependents, otherIncome, deductions, bonus, taxYear (2025 to compare) |
| UK | region = ruk | scotland, studentLoan = plan1 | plan2 | plan4 | plan5 | postgrad, pensionPct, taxCode |
| Canada | province (ON, QC, BC…), rrspPct |
| Australia | help (true/false), salarySacrifice |
| India | regime = new | old, pf, professionalTax, hra, deductions80c |
| Germany | steuerklasse I–VI, bundesland, kirche, children, age, zusatzbeitrag |
| France | statut = non-cadre | cadre, situation = single | couple | isole, children, mutuelle |
Every field the calculator form offers is accepted under the same name; anything you leave out takes the calculator's default. The exact set is in the open-data files' notes and on the methodology page.
GET /api/v1/solve — salary needed for a target take-home
curl 'https://paysums.com/api/v1/solve?country=US&state=TX&targetNet=5000&targetPeriod=monthly'Returns the gross salary (gross, grossInPeriod) that produces the target net, plus the full paycheck at that salary.
GET /api/v1/mortgage, /affordability, /refinance, /loan
curl 'https://paysums.com/api/v1/mortgage?price=450000&down=90000&years=30&taxPct=1.1&insurance=1800&pmiPct=0.6&extra=200'Omit rate to use this week's Freddie Mac 30-year average. Mortgage returns principal & interest, taxes, insurance, PMI (dropped at 78% LTV), total interest, payoff month and a year-by-year schedule; affordability takes income, debts, down, frontDti/backDti; refinance takes balance, rate, yearsLeft, newRate, newYears, closing; loan takes amount, years, rate.
GET /api/v1/sales-tax
curl 'https://paysums.com/api/v1/sales-tax?zip=60614&amount=250'By zip or state: statutory state rate, paysums' population-weighted average local rate, the published combined rate when the ZIP lies inside one of 40 major cities, the state's official address lookup URL, and the tax on amount (mode=remove to back it out of a receipt).
GET /api/v1/tables/<name> and /rates
us, uk, ca, au, in, de, fr, salestax, vat return the exact data file the calculators use (brackets, deductions, credits, payroll programs, with sources and as-of dates); /rates returns the weekly Freddie Mac averages and ECB exchange rates. Cached one hour; CC BY 4.0 — see open data for CSV downloads and the licence.
Pricing and keys
| Tier | Requests / day | Price | Use |
|---|---|---|---|
| Free | 100 per IP | $0, no key | prototypes, spreadsheets, personal tools, journalists |
| Pro | 10,000 | $29 a month | apps, HR and payroll tools, internal dashboards; key by email at checkout, cancel any time |
| Business | 100,000+ | from $99 a month | higher limits, uptime commitment, white-label widgets included — contact us |
Request a Pro key → (checkout opening shortly — we reply within a day)
Send the key as X-API-Key: … or ?key=…. Every response carries X-RateLimit-Remaining and X-Plan; over the limit you get HTTP 429 with a JSON message. Keys are verified on every call and cached for an hour.
Terms in one paragraph
The numbers are computed from the official 2026 tables and verified against the published government calculators (see the change log), but they are statutory estimates, not tax, legal or lending advice, and no warranty is given. Attribute “paysums.com” where the figures are shown to end users. Don't resell the raw feed as your own data product; do build products on it. Abuse of the free tier (rotating IPs, scraping the whole table space) gets blocked.
Frequently asked
How current are the tables?
A cloud routine checks the official sources every Monday and commits changes the same day; mortgage rates and exchange rates refresh every Thursday; the API reads the live files, so there is no version to pin — the response includes the tax year.
Do you store requests?
Only a per-IP or per-key daily counter for rate limiting, expiring after a day. No salaries or inputs are logged.
Can I run it on my own servers?
The engines are plain JavaScript and the tables are CC BY; a source licence for on-premise use is available under the Business tier.