Financial and developer calculators that actually explain the math

See how principal and regular contributions grow with compounding.

Find the monthly payment and total cost of any fixed-rate loan.

Estimate mortgage payments and the impact of extra payments.

Project the returns on a regular monthly investment plan.

Convert between hourly pay and annual salary.

Work out your total pay with regular and overtime hours.

Decide between paying down debt and investing.

Find how many units you must sell to cover your costs.

Measure return on investment and annualized return.

Find how long your investment takes to pay for itself.

Convert Unix timestamps to human-readable dates instantly.

See the time difference between two cities or timezones.

Turn CSV rows into clean JSON objects.

Export JSON arrays as spreadsheet-ready CSV.

Format, validate, and minify JSON with error locations.

Turn JSON into readable YAML with correct quoting.

Convert YAML files and snippets into valid JSON.

Encode and decode UTF-8-safe Base64 strings.

Shrink any image to a target file size like 50 KB or 100 KB.

Convert images between PNG, JPEG and WebP in one click.

Resize images to exact pixels with social-media presets.