calc
44 tools for exact, auditable math that never lies. Exact decimal & financial math (compound interest, loans & amortization, NPV/IRR/XIRR, CAGR/ROI, depreciation, full TVM: PMT/FV/PV/NPER/RATE, APR<->APY), unit conversion, dates / business-days / holidays, statistics (percentiles, quartiles, mode, correlation), cryptographically-secure RNG, and an exact-decimal expression evaluator. Audit receipt per call, no network, no PII.
How to pay
Subscribe
$9/month
Predictable monthly cost with included usage. Best for steady, high-volume traffic.
- Unlimited tools within plan limits
- One API key, billed once a month
- Cancel any time
calc — the calculator that never lies
LLMs are unreliable at arithmetic and silently wrong on money. calc gives your agent a deterministic, auditable compute engine: exact decimal math with no floating-point drift (0.1 + 0.2 == 0.3) and a verifiable receipt on every call.
44 tools
Money & finance — exact sums/products, tax, compound interest, amortizing loans & schedules, NPV, IRR, XNPV, XIRR, CAGR, ROI, break-even, depreciation, mortgage payoff, and full time-value-of-money: PMT / FV / PV / NPER / RATE, plus APR <-> APY.
Statistics — describe, percentile, quartiles, mode, correlation, covariance.
Dates — calendar & business days, recurrence, timezone conversion, public holidays by country.
Units — length, mass, volume, area, speed, data, time, temperature.
Utilities — cryptographically-secure RNG (seedable), dice, an exact-decimal expression evaluator (no eval), and fair bill splitting.
Great for
Invoicing & finance ops, fintech agents, reporting — anything where "looks right" isn't good enough. Exact Decimal, no network, no PII, audit receipt on every call.