Ratio & Proportion Calculator

Solve for x, simplify, split amounts

Solve a Proportion (leave one box empty)
:=:
Leave exactly one of the four boxes empty. Solved by cross-multiplication.
Simplify a Ratio
:
Split an Amount by Ratio
Common Screen & Photo Ratios
RatioTypical resolutionsUsed for
16:91920×1080 · 2560×1440 · 3840×2160(4K)Monitors · TV · YouTube
4:31024×768 · 1600×1200Older monitors · iPad
3:23000×2000 · 6000×4000Camera photos (FF/APS-C)
21:92560×1080 · 3440×1440Ultrawide
1:11080×1080Instagram square
9:161080×1920Shorts · Reels · Stories
FAQ
How do I solve for x in a proportion?
Use cross-multiplication: if 2:3 = 4:x then 2x = 12, so x = 6. Leave the unknown box empty above and it solves automatically.
How do I turn a ratio into percentages?
Divide each part by the total of the parts: 3:2 → 3/5 = 60%% and 2/5 = 40%%. The simplifier shows this alongside the reduced ratio.
What resolutions are 16:9?
1280×720 (HD), 1920×1080 (FHD), 2560×1440 (QHD) and 3840×2160 (4K). See the chart below for other aspect ratios.
How do I split $100 in a 3:2 ratio?
Divide by the sum of parts (5) to get a $20 unit, then multiply: $60 and $40. The split tool does this for any ratio.
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Proportions and ratios

A proportion a:b = c:d means the cross products are equal (b×c = a×d) — leave one value blank and the calculator solves it. Simplifying a ratio divides both sides by their greatest common factor, and the split tool divides any amount into shares that follow your ratio, handy for bills, recipes and settlements.

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