Ratio Calculator
Simplify ratios to lowest terms with GCD, solve missing proportion terms by cross multiplication, compare two ratios, and scale quantities with
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What is Ratio Calculator?
The Ratio Calculator works with ratios in four ways: it simplifies a ratio like 16:24 down to 2:3 using the greatest common divisor, solves for a missing term in a proportion such as 1:2 = x:8 via cross multiplication, checks whether two ratios are equivalent, and scales both terms by any factor. A built-in equivalent-ratio table shows ×2 through ×10 at a glance. Everything runs offline in your browser.
Key Benefits
- Reduce ratios to lowest terms instantly, decimals included
- Solve proportions with any one of the four terms unknown
- Verify equivalence between two ratios before using them interchangeably
- Scale recipes, maps, drawings, and models with confidence
- 100% client-side — no uploads, no sign-up, works offline
Common Use Cases
- •Resizing a recipe from 4 servings to 6 without guessing the amounts
- •Checking map scale conversions and model-to-real-world dimensions
- •Verifying financial ratios like debt-to-equity across two periods
- •Solving classroom proportion problems and checking homework answers
- •Mixing paint, concrete, or ingredients to an exact specification ratio
How to Simplify, Solve, Compare, and Scale Ratios
- Pick a mode: Choose Simplify, Solve Missing Term, Compare, or Scale from the tab bar — each tab has its own fields.
- Enter your numbers: Type your values; on the Solve tab leave exactly one of A:B = X:D empty and the missing term appears via cross multiplication.
- Read the extras: Simplify also shows decimal, percent, GCD, and an equivalent-ratio table; Compare tells you whether two ratios are equal or which one is greater.
- Copy the result: Press Copy on the Simplify or Scale result to grab the ratio, then switch to another tab if you need a second operation.
Key Features
- Simplify any ratio, including decimals, to lowest terms with GCD math
- Solve for any missing term in a proportion via cross multiplication
- Compare two ratios for equivalence with decimal and percent views
- Scale ratios by any factor and copy results to the clipboard
- Equivalent-ratio table from ×2 to ×10 for quick reference
Frequently Asked Questions
Can it simplify ratios with decimals?
Yes — enter numbers like 2.5:3.5 in the Simplify tab and it reduces them to lowest terms, showing the decimal value, the percentage, and the GCD that was divided out.
How do I solve for an unknown term?
Open the Solve Missing Term tab, fill in any three of A:B = X:D, and leave the unknown blank. It applies cross multiplication (A × D = B × X) and fills in the answer as you type.
What is the equivalent ratios table for?
After simplifying, it lists the same ratio multiplied by 2, 3, 4, and beyond — useful for scaling recipes, drawings, or batch sizes while keeping the proportions identical.
Does anything leave my browser?
No — every calculation happens locally, so your numbers never leave the browser, and the Copy button lets you paste results straight into a document or chat.