Ratio Calculator | Proportions & Multi-Part Ratios

Divide both sides of the ratio by their greatest common divisor (GCD). For example, 10:15 simplifies to 2:3 by dividing both by 5. Enter any ratio and this calculator simplifies it instantly.

Use cross-multiplication. If A:B = C:x, then A*x = B*C, so x = (B*C) / A. Enter three known values in the proportion solver and the calculator finds the fourth automatically.

A ratio compares two quantities (e.g., 3:4). A proportion states that two ratios are equal (e.g., 3:4 = 6:8). Use the proportion solver in this calculator to find a missing value when one ratio is known and the other is partially known.

Add all parts (2+3+5=10), then divide the total by 10 to get one part, and multiply by each ratio number. For example, splitting $100 in a 2:3:5 ratio gives $20, $30, and $50. Use the multi-part split mode in this calculator to do this for any number of parts.

Yes! In guest mode, you can export your calculations to JSON format. Sign in is required for PDF and CSV export. Click the export button to download your results. This is perfect for record-keeping, sharing with others, or importing into other tools.

Yes! Your calculation history is automatically saved. Guest users can save up to 50 calculations per workspace locally. Sign in for free to save up to 100 calculations per workspace, with access from any device when logged in.

Absolutely! The Ratio Calculator is completely free with no sign-up required. Create a free account to unlock additional features like more calculation history, multiple workspaces, and the ability to access your saved data from any device.