The Open Source Calculation Library

Estimate your body fat percentage using the standard US Navy circumference-based equations. Supports both US Imperial and Metric systems.

Calculate your periodic mortgage or loan payments, see the impact of extra payments, and estimate how much interest you can save.

Solve quadratic equations of the form ax² + bx + c = 0. Calculate real and complex roots, vertex coordinates, and plot key characteristics.

The Swiss Army Knife of conversions. Instantly convert Length, Weight, Volume, and Temperature between US Imperial and Metric systems.

Estimate your weekly, fortnightly, or monthly take-home pay under the new 2024-2025 Revised Stage 3 tax cuts.

Check your Body Mass Index (BMI) instantly. Supports both Metric (cm/kg) and Imperial (ft/lbs) units with accurate health categories.

Visualize the power of compound interest with monthly contributions. See how small savings grow into massive wealth over time.

Plot multiple linear equations (y=mx+b), find intersection points, and calculate x/y intercepts instantly with interactive graphs.

Calculate exactly how many survey responses you need for statistically significant results. Supports finite population correction.

The only percentage tool you need. Calculate percentage increases, find parts of a whole, and solve ‘X is what percent of Y’ problems instantly.