🔄 Metric ↔ Imperial Converter

Convert between metric and imperial units. Length results include fractional inches (e.g. 3 3/8″) and feet + inches (e.g. 5′ 10 1/2″) for real-world accuracy.

Millimeters (mm)

Inches (in)

Result

💡 A dime is about 1.35 mm thick (0.053 in)

⚡ Quick Reference

Marathon

42.195 km

= 26.2 mi

Body weight (avg)

70 kg

= 154 lb

Boiling point

100°C

= 212°F

Freezing point

0°C

= 32°F

Gallon of milk

3.79 L

= 1 gal

Height (5'10")

178 cm

= 70 in

📐 Common Formulas

km → mi: divide by 1.609

mi → km: multiply by 1.609

kg → lb: multiply by 2.205

lb → kg: divide by 2.205

°C → °F: × 9/5 then + 32

°F → °C: − 32 then × 5/9

L → gal: divide by 3.785

gal → L: multiply by 3.785

How This Tool Works

This converter specializes in the most common metric-to-imperial and imperial-to-metric conversions that people encounter daily. It covers length (cm/inches, meters/feet, km/miles), weight (kg/lbs, grams/ounces), volume (liters/gallons, mL/cups), and temperature (°C/°F). Unlike a general unit converter, it is optimized for speed with preset pairs and instant two-way conversion as you type, making it ideal for quick lookups while cooking, shopping internationally, interpreting medical records, or understanding foreign measurements.

💡 Tips & Best Practices

1Quick mental math: multiply km by 0.6 for miles, multiply kg by 2.2 for pounds, multiply cm by 0.4 for inches.
2Body temperature: 37°C = 98.6°F. A fever is typically 38°C / 100.4°F or above.
3For cooking, US cups to mL: 1 cup = 237 mL, ½ cup = 118 mL, ¼ cup = 59 mL.

Frequently Asked Questions

Which countries use the imperial system?

Only the United States, Liberia, and Myanmar have not officially adopted the metric system. However, the UK uses a hybrid system — miles and pints (imperial) alongside meters, liters, and kilograms (metric).