Metric to Imperial Conversion: Complete Guide for Americans and Travelers

Why Learn Metric to Imperial Conversion?

The United States is one of only three countries not using the metric system. Whether you're an American traveling abroad or an international visitor to the US, understanding both systems is essential.

Quick Reference Chart

Metric	Imperial	Conversion
1 kilometer	0.621 miles	km × 0.621
1 meter	3.281 feet	m × 3.281
1 centimeter	0.394 inches	cm × 0.394
1 kilogram	2.205 pounds	kg × 2.205
1 gram	0.035 ounces	g × 0.035
1 liter	0.264 gallons	L × 0.264
0°C	32°F	(°C × 1.8) + 32

Length Conversions

Kilometers to Miles

Formula: miles = kilometers × 0.621371

Quick Mental Math: Multiply km by 0.6 (close enough for estimates)

• 50 km ≈ 30 miles
• 100 km ≈ 60 miles

Meters to Feet

Formula: feet = meters × 3.28084

Quick Mental Math: Multiply meters by 3.3

• 10 m ≈ 33 feet

Centimeters to Inches

Formula: inches = centimeters × 0.393701

Quick Mental Math: Divide cm by 2.5

• 10 cm ≈ 4 inches

Common Height Conversions

Metric	Imperial
150 cm	4'11"
160 cm	5'3"
170 cm	5'7"
180 cm	5'11"
190 cm	6'3"

Weight Conversions

Kilograms to Pounds

Formula: pounds = kilograms × 2.20462

Quick Mental Math: Double the kg and add 10%

• 70 kg → 140 + 14 = 154 lb

Common Weight Conversions

Metric	Imperial
50 kg	110 lb
60 kg	132 lb
70 kg	154 lb
80 kg	176 lb
100 kg	220 lb

Temperature Conversion

Celsius to Fahrenheit

Formula: °F = (°C × 9/5) + 32

Quick Mental Math: Double °C and add 30

• 20°C → 40 + 30 = 70°F (actual: 68°F)

Temperature Reference Points

Condition	Celsius	Fahrenheit
Very cold	-10°C	14°F
Freezing	0°C	32°F
Cool	10°C	50°F
Comfortable	20°C	68°F
Hot	30°C	86°F
Body temp	37°C	98.6°F

Volume Conversions

Liters to Gallons (US)

Formula: US gallons = liters × 0.264172

Quick Mental Math: Divide liters by 4

• 8 L ≈ 2 gallons

Speed Conversions

Kilometers per Hour to Miles per Hour

Formula: mph = km/h × 0.621371

Speed Limit Conversions

Metric	Imperial
50 km/h	31 mph
80 km/h	50 mph
100 km/h	62 mph
120 km/h	75 mph

Memory Tricks

The Fibonacci Approximation (km ↔ miles)

Adjacent Fibonacci numbers approximate km-to-miles conversion:

• 5 km ≈ 3 miles
• 8 km ≈ 5 miles
• 13 km ≈ 8 miles

Temperature Landmarks

Memorize these key points:

• 0°C = 32°F (freezing)
• 10°C = 50°F
• 20°C = 68°F
• 30°C = 86°F

Conclusion

Metric to imperial conversion becomes second nature with practice. Focus on memorizing a few key conversions and mental math tricks.

Use our free Unit Converter tool for accurate conversions whenever you need them.