Height Comparison Calculator — Compare Two Heights

How height comparison works

Comparing heights is a subtraction, then two ways of expressing the answer. First turn both heights into the same unit: feet and inches become total inches (feet times 12 plus inches), and centimetres become inches by dividing by 2.54 — one inch is exactly 2.54 centimetres. Then subtract the shorter from the taller: that is the difference, in inches and in centimetres. The ratio is the taller height divided by the shorter height, and the percent taller is the difference divided by the shorter height, times 100. The percent is measured against the shorter person, which is the part people most often get wrong: 6 inches on a 64-inch person is 9.4%, but the same 6 inches on a 72-inch person is only 8.3%.

At the defaults — Person A 5 ft 10 in and Person B 5 ft 4 in — the heights in inches are 5 × 12 + 10 = 70 in and 5 × 12 + 4 = 64 in. The difference is 70 − 64 = 6 in, and 6 × 2.54 = 15.2 cm. The ratio is 70 ÷ 64 = 1.094, and the percent taller is 6 ÷ 64 × 100 = 9.4%. In centimetres the heights are 70 × 2.54 = 177.8 cm and 64 × 2.54 = 162.6 cm.

The worked example, line by line

Setup: Person A 5 ft 10 in, Person B 5 ft 4 in; find who is taller, by how much, and by what percentage.

Line 1 — turn both heights into inches. Person A: 5 × 12 + 10 = 70 in. Person B: 5 × 12 + 4 = 64 in.

Line 2 — the difference in inches. 70 − 64 = 6 in. Person A is taller.

Line 3 — the difference in centimetres. 6 × 2.54 = 15.2 cm.

Line 4 — the ratio. 70 ÷ 64 = 1.094.

Line 5 — the percent taller. 6 ÷ 64 × 100 = 9.4%. Person A is 9.4% taller than Person B.

Line 6 — the heights in centimetres. Person A: 70 × 2.54 = 177.8 cm. Person B: 64 × 2.54 = 162.6 cm.

Every branch, checked

6 ft 2 in vs 5 ft 9 in: 74 inches against 69 inches — a difference of 5 in (12.7 cm), a ratio of 74 ÷ 69 = 1.072, and 5 ÷ 69 × 100 = 7.2% taller. Five inches looks smaller here than the default’s six, and the percentage agrees: on a taller base, the same inches count for less.

5 ft 0 in vs 6 ft 0 in: 60 inches against 72 inches — Person B is taller by 12 in (30.5 cm), a ratio of 72 ÷ 60 = 1.200, and 12 ÷ 60 × 100 = 20.0% taller. A full foot of difference is the biggest gap on this page, and the percentage shows it: the shorter person would have to grow a fifth of their height to catch up.

170 cm vs 185 cm: in inches that is 170 ÷ 2.54 = 66.9 in against 185 ÷ 2.54 = 72.8 in — a difference of 15 cm (5.9 in), a ratio of 185 ÷ 170 = 1.088, and 15 ÷ 170 × 100 = 8.8% taller. The centimetre boxes work exactly like the feet-and-inches boxes; only the input unit changes.

Reverse — Person A 5 ft 10 in, 6 in taller: Person B is 70 − 6 = 64 in, which is 5 ft 4 in (162.6 cm). The reverse is the forward comparison run backwards: the difference subtracted from the taller height gives the shorter one.

What the defaults assume

The calculator assumes the heights you enter are standing heights measured without shoes, in the morning — people are about a centimetre taller in the morning than in the evening, because the discs in the spine compress during the day, so a comparison measured at different times of day can be off by that much. It assumes 1 inch is exactly 2.54 centimetres, which is the international definition, not an approximation. It does not account for posture, footwear, or hair: shoes add 2 to 4 centimetres, and a tall hairstyle adds more, so two people compared in shoes are not being compared on the same basis. The percent taller is always measured against the shorter person — that is the standard way to say how much taller someone is — and the ratio is always taller divided by shorter, so it is never below 1. Rounding convention: inches and centimetres are computed from unrounded values and shown to one decimal; the ratio is shown to three decimals and the percentage to one decimal.

Output · formula · meaning

Who uses this

• The couple settling a friendly argument: 5 ft 10 in against 5 ft 4 in — they learn the gap is 6.0 in (15.2 cm) and Person A is 9.4% taller, which ends the debate with a number instead of a shrug.
• The parent tracking a teenager’s growth: last year 5 ft 9 in, now 6 ft 2 in — they learn the growth is 5 in (12.7 cm) in a year, a ratio of 1.072 against last year’s height, and they can watch the number each birthday.
• The online dater checking a profile: 170 cm against their own 185 cm — they learn the difference is 15 cm (5.9 in) and 8.8%, which is easier to picture than two bare numbers in different units.
• The costume designer fitting a cast: the lead is 5 ft 10 in and the understudy is 6 in shorter — they learn the understudy is 5 ft 4 in (162.6 cm), so the hems and the sightlines both need adjusting.

Accuracy & limitations

The arithmetic is exact: feet and inches convert to total inches, centimetres divide by exactly 2.54, and the difference, ratio and percentage follow from those numbers with no estimation. What the calculator cannot do is measure you: heights change by about a centimetre between morning and evening, shoes add 2 to 4 centimetres, and self-reported heights are usually rounded up — people tend to add an inch to themselves. Two heights measured at different times of day, one in shoes and one barefoot, can disagree by several centimetres before the calculator ever sees them. For the same reason, a difference of less than an inch is not worth arguing about: it is inside the noise of posture and time of day. For body mass at your height, see BMI calculator; for converting centimetres to inches on their own, see cm to inches.