Ratio Tool

Explore two-part ratios with simplified forms, equivalent values, proportional allocations, and side-by-side comparisons. Adjust decimal precision, swap terms, inspect percentages and detailed results, and view responsive charts for clearer understanding of proportional relationships.

Ratio calculatorEnter positive values or zero where applicable
A
B
Simplified ratio
16 : 9
Already in its simplest form

Ratio breakdown

Relative share of both terms

100% total
AB
64%36%

Detailed results

Values and formulas at a glance

MeasureValue

Table of Contents

  1. How Ratio Tool Works?
  2. Practical Use Cases
  3. Accuracy and Limitations
  4. Frequently Asked Questions (FAQs)
  5. Cite This tool

Highlights

  • Simplify whole-number and decimal ratios
  • Solve missing terms in equivalent ratios
  • Split totals into proportional shares
  • Compare ratios using cross-products
  • Visualise percentages and export CSV, JSON or PNG

How Ratio Tool Works?

A ratio expresses the relative sizes of two quantities as A : B. To simplify a ratio, express both terms as whole numbers and divide them by their greatest common divisor (GCD). For decimal terms, the tool first scales both values by a power of ten, using up to eight decimal places.

g=GCD(A,B),A:B=Ag:Bg

Equivalent ratios multiply both terms by the same factor. Given a new first term X and an original ratio A : B, the corresponding second term is X × B ÷ A. Conversely, given a new second term Y, the first term is Y × A ÷ B.

X:X×BA=A:B

To split a total T in the ratio A : B, allocate T × A ÷ (A + B) to the first part and T × B ÷ (A + B) to the second part. A comparison of A : B and C : D checks whether the cross-products A × D and C × B match. Scaling multiplies or divides both terms by the chosen factor.

TA=T×AA+B,TB=T×BA+B

ModeExampleOutcome
Simplify16 : 82 : 1
Equivalent3 : 2, new A = 1212 : 8
Split a total3 : 2, total = 10060 and 40
Compare2 : 3 versus 4 : 6Equal ratios
Scale2 : 3 multiplied by 48 : 12

The results also show both term shares as percentages of their sum, the sum, absolute difference, and quotients where defined. A stacked bar and chart illustrate the proportions.

Practical Use Cases

Home cooks: Scale a 2 : 3 ingredient proportion for a larger recipe while preserving the flavour balance.

Teachers and students: Reduce ratios to simplest form, solve missing equivalent terms, and check exercises through cross-products.

Designers: Compare two width-to-height proportions to see whether layouts preserve the same relative dimensions.

Project managers: Divide a shared total between two teams according to a chosen workload ratio, then review each team’s percentage share.

Small business owners: Split a promotional budget across two activities using a target allocation ratio and inspect the resulting amounts.

Sports analysts: Compare two non-negative performance ratios and visualise each side’s share of the combined figures.

Accuracy and Limitations

The tool uses browser JavaScript floating-point arithmetic and displays results to 2, 4, 6, or 8 decimal places. Decimal simplification considers at most eight fractional digits and may become unavailable when scaled terms exceed JavaScript’s safe-integer range. Inputs must be finite and non-negative; both ratio terms cannot be zero. Equivalent-term solving requires a non-zero original term on the selected side, and dividing by a zero scale factor is rejected. Ratio comparisons use a relative cross-product tolerance of 1 × 10−10, so extremely close ratios may be labelled equal. With a zero denominator, the corresponding quotient is undefined; chart percentages are relative to the two-term sum.

Frequently Asked Questions

A ratio compares two quantities by division and is commonly written as A : B. The order of the terms matters.

Divide both terms by their greatest common divisor, 6. The simplified ratio is 3 : 4.

Yes. Multiplying both terms of 2 : 3 by 4 gives 8 : 12.

There are five equal shares in total. The two portions are 60 and 90.

Yes, 0 : 5 is a valid ratio, but 0 : 0 is indeterminate. Division by a zero second term is undefined.

Cite This tool