About Figured
Figured is a collection of free calculators for tax, paycheck, finance, health, and everyday questions. Every result shows the arithmetic behind it — not just a number — and every formula and constant we use is either standard and cited, or checked against an independent source.
What this site is
Most calculators online hide their math. Figured doesn't: every calculator page includes a breakdown of the calculation, a plain-language explanation of the formula, and a sources section linking to where the numbers came from (IRS publications, government agencies, or established financial formulas). The goal is a result you can verify yourself, not just take on faith.
Figured is independently built and maintained. It is not affiliated with the IRS, the Social Security Administration, or any government agency, employer, lender, or financial institution referenced in its calculators.
How a calculator gets built
Every calculator starts from a written spec listing its inputs, its formula, and a set of "golden vector" test cases — known correct answers for known inputs. The calculator's logic is written and tested against those vectors before it's published, and it stays published only as long as the underlying rule (a tax bracket, a contribution limit, a formula) hasn't changed. When a rule changes, the calculator is updated and its "last updated" date moves.
Our verification tiers
Every calculator on Figured is labeled Tier A, B, or C. The tier tells you how its numbers were checked, and it's meant to help you judge how much scrutiny a given result has been through — not to rank calculators by importance.
Tax & paycheck calculators
The highest bar. Every test case is checked against an independent source — an IRS worked example, the text of a statute, or a recorded cross-check against an established payroll calculator (like ADP or SmartAsset). Nothing is estimated from memory.
Financial & health formulas
Standard, published, closed-form formulas — compound interest, loan amortization, calorie/metabolism equations. At least one test case is hand-computed from the formula itself, plus generated edge cases (like a 0% interest rate) to catch mistakes at the boundaries.
Everyday utilities
Straightforward, unambiguous math — percentages, date differences, unit conversions. There's no external authority to cite for "10% of 50," so these are verified with generated test cases covering the full range of inputs instead.
You can see a calculator's tier when browsing its category page, and every calculator page lists its sources (where applicable) and a "last updated" date.
What Figured isn't
Nothing on this site is tax, legal, financial, or medical advice — every calculator links to the disclaimer that applies to its category. Results are estimates based on the inputs you provide and the rules in effect when a calculator was last updated; they can differ from your actual tax return, paycheck, loan terms, or health outcome. When in doubt, check with a qualified professional or the primary source cited on the calculator page.
Contact
Found an error, have a source correction, or a calculator you'd like to see built? Reach us at [email protected].
13 calculators published · 11 Tier A (statute/IRS-sourced)