Does it add up?

Fast, private calculators and games. All math runs in your browser — nothing stored on any server.

Calculators

Clean 4-function calc. Keyboard shortcuts included.

Trig, logs, powers, memory, and 2nd-function layer.

Plot up to 3 functions. Pan and zoom. Canvas-based.

Ask a question. Shake the ball. All 20 classic answers.

Split the bill and figure out who owes what.

Monthly payment, total interest, principal vs interest bar.

X% of Y, what % is X of Y, and percent change.

Body mass index with imperial/metric toggle and gauge.

Convert between hourly, weekly, monthly, and annual pay.

Games

Select numbers that sum to exactly 10. Race the clock and beat your high score.

A fresh cross-sum puzzle every day. Fill the grid, track your streak.