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How to Convert Units: Quick Reference for Everyday Conversions

5 min read •
Beginner Units Convert Measurement Reference

"How many cups in a liter?" "What is 72 degrees Fahrenheit in Celsius?" "How many kilometers is 5 miles?" These are some of the most searched questions on the internet, every single day.

This guide is a quick reference for the most common conversions, plus a free tool to convert anything instantly.

Convert Any Unit Now

Use our free Unit Converter — supports length, weight, temperature, volume, area, speed, time, and data units. Select a category, pick your units, and get instant results.

Temperature

The conversion everyone needs and nobody remembers.

Formulas

Celsius to Fahrenheit:  °F = (°C × 9/5) + 32
Fahrenheit to Celsius:  °C = (°F - 32) × 5/9

Quick Reference

°F °C What It Feels Like
32 0 Freezing point of water
50 10 Cold — jacket weather
68 20 Room temperature
72 22 Comfortable indoor temp
77 25 Warm
86 30 Hot summer day
98.6 37 Normal body temperature
100 38 Fever
104 40 Very hot day / high fever
212 100 Boiling point of water
350 177 Oven — baking
400 204 Oven — roasting
450 232 Oven — pizza

Quick Estimate Trick

°F to °C: Subtract 30, divide by 2. Example: 80°F → (80-30)/2 = 25°C (actual: 26.7°C — close enough)

°C to °F: Multiply by 2, add 30. Example: 25°C → 25×2+30 = 80°F (actual: 77°F — close enough)

Weight

Metric ↔ Imperial

Metric Imperial Common Use
1 kg 2.205 lbs Body weight, luggage
1 lb 0.454 kg Cooking, packages
1 oz 28.35 g Food labels, recipes
100 g 3.53 oz Nutrition labels

Common Conversions

Want to convert Multiply by
kg → lbs × 2.205
lbs → kg × 0.454
oz → g × 28.35
g → oz × 0.035
stone → lbs × 14
stone → kg × 6.35

Quick Estimates

kg to lbs: Double it and add 10%. Example: 70 kg → 140 + 14 = 154 lbs (actual: 154.3 — very close!)

lbs to kg: Halve it and subtract 10%. Example: 150 lbs → 75 - 7.5 = 67.5 kg (actual: 68 kg)

Length / Distance

Common Conversions

From To Factor
1 inch 2.54 cm
1 foot 30.48 cm
1 yard 0.914 m
1 mile 1.609 km
1 cm 0.394 inches
1 meter 3.281 feet
1 km 0.621 miles

Quick Reference

Miles Kilometers
1 1.6
5 8
10 16.1
26.2 (marathon) 42.2
50 80.5
100 160.9

Quick estimate: Miles to km — multiply by 1.6. km to miles — multiply by 0.6.

Height Conversions

Feet/Inches cm
5'0" 152
5'4" 163
5'6" 168
5'8" 173
5'10" 178
6'0" 183
6'2" 188
6'4" 193

Volume (Cooking)

US Measurements

Measure ml Tablespoons
1 teaspoon (tsp) 5 ml 1/3 tbsp
1 tablespoon (tbsp) 15 ml 1
1 fluid oz 30 ml 2
1/4 cup 60 ml 4
1/3 cup 80 ml 5.3
1/2 cup 120 ml 8
1 cup 240 ml 16
1 pint 473 ml 32
1 quart 946 ml 64
1 gallon 3,785 ml 256

Cups ↔ Liters

Cups Liters
1 0.24
2 0.47
4 (1 quart) 0.95
8 (half gallon) 1.89
16 (1 gallon) 3.79

US vs UK

Measure US UK
1 cup 240 ml Not standard (UK uses ml)
1 pint 473 ml 568 ml
1 gallon 3,785 ml 4,546 ml

UK measurements are about 20% larger. A UK pint of beer is bigger than a US pint.

Speed

km/h mph
30 18.6
50 31.1
80 49.7
100 62.1
120 74.6
160 99.4

Quick estimate: km/h to mph — multiply by 0.6. mph to km/h — multiply by 1.6.

Data / Storage

Unit Equals
1 KB 1,024 bytes
1 MB 1,024 KB
1 GB 1,024 MB
1 TB 1,024 GB

Real-World References

Size What It Holds
1 MB One high-quality photo
5 MB One MP3 song
1 GB ~250 songs or 1,000 photos
4.7 GB One DVD
25 GB One Blu-ray disc
50 GB ~10 hours of HD video
1 TB ~250,000 photos or 500 hours of video

For data conversions, also try our Byte Converter.

Convert Instantly

Use our free Unit Converter for any conversion — length, weight, temperature, volume, area, speed, time, and data. Select your units and get instant results.

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