How it works
Height conversion rests on fixed definitions: one inch = 2.54 centimetres exactly (international yard-pound agreement, 1959), one foot = 12 inches, one metre = 100 centimetres. To convert feet and inches to centimetres, total inches = feet × 12 + inches, then cm = total inches × 2.54. To convert centimetres to feet and inches, total inches = cm ÷ 2.54, feet = floor(total inches ÷ 12), remaining inches = total inches mod 12. Metres = cm ÷ 100. Worked example — 5 ft 10 in: total inches = 5×12 + 10 = 70 in. Centimetres = 70 × 2.54 = 177.8 cm. Metres = 1.778 m. Reverse: 178 cm → 70.08 in → 5 ft 10.1 in. Medical and BMI contexts use centimetres or metres; US driver's licences and sports listings often use feet-inches. Rounding matters on forms: some require whole centimetres, others one decimal. The converter preserves precision internally and displays sensible rounding. Do not confuse height in feet alone (5 ft) with 5 ft 0 in versus 5 ft 10 in — always capture inches separately for accuracy.
Formula
cm = (feet × 12 + inches) × 2.54 | feet = floor(cm / 2.54 / 12) | inches = (cm / 2.54) mod 12
Tips
- Measure height standing straight against a wall — shoes off for medical consistency.
- 5 ft 10 in is 70 inches total — do not enter 5.10 as a decimal foot value.
- BMI and TDEE tools expect centimetres; convert here first if you know feet/inches.
- Reverse mode accepts decimal cm (175.5) for precise clinical records.
Frequently asked questions
- How many cm is 5 feet 10 inches?
- 177.8 cm (70 inches × 2.54). That is 1.778 metres.
- How tall is 178 cm in feet and inches?
- 178 cm = 70.08 inches ≈ 5 feet 10.1 inches.
- Why use 2.54 exactly?
- The inch has been defined as exactly 2.54 cm since 1959. All modern conversion uses this constant — no rounding to 2.5.
- Feet and inches or cm for BMI?
- The BMI engine on this site expects kilograms and centimetres. Convert height here, then use the BMI calculator.