Index

Calculators

Each tool is a separate page with its own formula, error states, and a result you can copy. Filter the list by name if you already know which question you want to answer.

Percentage calculator

Find a percent of a number, what percent one number is of another, or percent change.

Tip calculator

Figure a restaurant tip, a total, and an even split from a bill and a percent.

Discount calculator

Take one or two percent-off discounts from a list price and see what you save.

Markup calculator

Compare markup and margin from a cost and a selling price, or from a target rate.

Sales tax calculator

Add or remove a sales tax percent that you enter. There is no built-in state table.

Bill split calculator

Split a check or line items, add an optional tip, and round leftover cents in the open.

Compound interest calculator

Project a future value with P × (1 + r ÷ n)^(n × t). Educational figures only.

Unit price calculator

Compare two packages by dollars per unit and highlight the cheaper unit price.