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Ratio Calculator - Calculatrice en ligne gratuite

Simplify ratios, scale them up or down, and solve A:B = C:D for the missing term. Useful for cooking conversions, business splits, scale models and any proportional reasoning.

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Simplified ratio

2 : 3

Original: 24 : 36 (divided by 12)

Une partie du contenu est encore affichée en anglais.

À propos

Comprendre : Ratio Calculator

Ratios are everywhere in everyday Indian life - cooking (rice:water = 1:2 for steamed basmati, 1:1.5 for pressure cooker), business partnerships (profit share in say 3:2:1 ratio for three partners), aspect ratios (16:9 for widescreen TVs, 3:2 for DSLR photos, 4:3 for legacy displays), financial ratios (debt-to-equity, current ratio, P/E), map scales (1:50,000 for topographic maps), gear ratios in vehicles, concrete mixes (1:2:4 for cement:sand:aggregate in M15 grade), and statistics (sex ratio, dependency ratio). This calculator handles three operations: simplification (reducing to lowest terms), scaling (multiplying through by a factor), and solving (finding a missing term in A:B = C:D proportions).

Class 5-10 mathematics introduces ratios early because they're a building block for fractions, percentages, proportions, similar triangles, and probability. JEE/NEET aspirants use ratios in mole concept (chemistry), specific heat and density problems (physics), and combination/permutation problems. The cross-multiplication shortcut (A/B = C/D → AD = BC) is one of the most-used algebraic moves in school math. This calculator gives instant answers plus the formula so you can build intuition for ratio reasoning.

Mode d’emploi

Utiliser Ratio Calculator en 3 étapes

  1. Pick mode: simplify, scale, or solve missing term.

  2. Enter the parts of the ratio.

  3. Read the simplified or scaled result.

La formule

Comment fonctionne Ratio Calculator

Simplification divides every part by their greatest common divisor. Scaling multiplies every part by the same factor to match a known new value. Solving uses cross-multiplication: A/B = C/D means A × D = B × C.

Formula

Simplified: divide all parts by GCD Scaled: A : B → k·A : k·B Solve: A/B = C/D → A·D = B·C

  • GCDGreatest common divisor
  • kScale factor
Les maths

Comment Ratio Calculator obtient son résultat

Simplification: a ratio A:B is in simplest form when GCD(A, B) = 1. The calculator divides both terms by their greatest common divisor. Example: 12:18 has GCD 6, so simplified ratio is 2:3. For three-part ratios like 6:9:15, divide all three by GCD(6, 9, 15) = 3, giving 2:3:5. Multi-part ratios work similarly. Decimals can be eliminated by multiplying through - 1.5:2.5 = 15:25 = 3:5.

Scaling: given a ratio A:B and a known new value C for term A, solve for the new value of B. If A:B = 3:5 and you scale A to 12 (factor of 4), B becomes 5 × 4 = 20. Used in cooking (recipe for 4 scaled to serve 6), business (profit share when total profit changes), drawings (scaling architectural drawings from 1:100 to 1:50), and unit conversions.

Solving for missing term: cross-multiplication. A/B = C/D implies A × D = B × C. So if 3/4 = x/20, then 3 × 20 = 4x → x = 15. This is the foundation of proportion-based problem-solving and underlies similar triangles, percentages, currency conversion, and rate-time-distance problems. Cross-multiplication works for any 2-term ratio comparison.

Exemples

Exemples résolus

Business profit split: ₹3,00,000 in ratio 5:3:2 among 3 partners

Total parts: 5+3+2 = 10. Each part: 3,00,000 / 10 = ₹30,000. Distribution: ₹1,50,000 (partner A), ₹90,000 (partner B), ₹60,000 (partner C). Common in startup co-founder splits and family business divisions.

Concrete mix M15: cement:sand:aggregate = 1:2:4, need 2 m³ concrete

Total parts: 1+2+4 = 7. Per part: 2/7 = 0.286 m³. Cement: 0.286 m³ × 1440 kg/m³ density = 412 kg ≈ 8.2 bags. Sand: 0.572 m³ ≈ 6.4 ft³. Aggregate: 1.143 m³ ≈ 40 ft³.

Photo aspect ratio: print 6×4 inch from a 4032×3024 phone photo

Original ratio: 4032:3024 = 4:3. Target: 6:4 = 3:2. Different aspect - will require cropping (either top/bottom strip or sides) to print exactly 6×4 without distortion.

Cas d’usage

Quand utiliser Ratio Calculator

  • Class 5-10 mathematics - ratio and proportion chapter homework and exam prep.
  • Cooking - scaling recipes up or down for different number of servings.
  • Business partnership - splitting profits, losses or capital contributions.
  • Architecture and engineering - concrete and mortar mix proportions.
  • Photography - aspect ratio cropping and print sizing.
  • Map reading - scale conversions (1:50,000 to actual distance).
  • Finance - analyzing P/E ratio, debt-to-equity, current ratio.
  • Chemistry - stoichiometric ratios in chemical equations.
Attention

Erreurs et pièges courants

  • Treating ratio as a fraction interchangeably without context. 2:3 means 2 parts out of total 5, not 2/3.
  • Forgetting to add all parts to get the total when distributing. Splitting ₹100 in 2:3 ratio means 5 parts total, ₹20 per part.
  • Reducing ratios incorrectly. 6:8 simplifies to 3:4 (divide by 2), not 1:1 (subtraction is wrong).
  • Mixing units in a ratio. Both terms must be in same unit (rupees:rupees, kg:kg).
  • Using decimal ratios when fractions are cleaner. 1.5:1 = 3:2 is clearer.
Conseils d’expert

Tirez le meilleur de cet outil

  • Always reduce to simplest form. 6:10 = 3:5 is easier to read and remember.
  • For three-part splits, compute total parts first, then per-part value, then multiply.
  • Use cross-multiplication for any proportion (A:B = C:D) problem.
  • Aspect ratios: phones 9:19.5 or 9:20, photos 4:3 or 3:2, video 16:9 or 21:9 (cinematic).
  • Pair with the percentage, fraction and proportion calculators on this site for related work.
FAQ

Questions sur Ratio Calculator

Ratio vs fraction - what's the difference?

Same idea, different notation. 3:4 means 3 parts to 4 parts; 3/4 means 3 quarters of a whole. Mathematically interchangeable.

Can ratios be reduced like fractions?

Yes. 6:8 = 3:4 (divide both by 2). The simplest form has no common factors greater than 1.

How do I split money in a ratio?

If splitting ₹1000 in 2:3, total parts = 5. Each part = 1000/5 = ₹200. Distribute: 2×200 = ₹400 and 3×200 = ₹600.

What is a unit ratio?

A ratio with one term equal to 1, like 1:8 (one teacher per 8 students). Convert any ratio to unit form by dividing both terms by the smaller.

How are ratios used in cooking?

Recipes often scale by ratio. Rice:water = 1:2 means 1 cup rice needs 2 cups water. Doubling rice (2 cups) needs 4 cups water.

Can a ratio have decimals?

Yes - 1.5:1 is valid. But for cleaner results, multiply through to eliminate decimals: 1.5:1 = 3:2.

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The Ratio Calculator is part of the Math suite on Online Calculator Tools, alongside 6 related calculators. All tools share the same UI patterns, the same privacy-first rendering (nothing is sent to a server), and the same commitment to showing the formula and assumptions behind every result.