Metric to Standard Conversions

Essential Conversions

You don't need to memorize dozens of conversions. These are the ones that come up most often.

Length

Metric	Standard	Approximate
1 cm	0.394 inches	≈ 0.4 in
2.54 cm	1 inch	exact
1 meter	3.281 feet	≈ 3.3 ft
1 km	0.621 miles	≈ 0.6 mi
1.609 km	1 mile	≈ 1.6 km

Weight / Mass

Metric	Standard	Approximate
1 gram	0.035 ounces	a paperclip
28.35 g	1 ounce	≈ 28 g
1 kg	2.205 pounds	≈ 2.2 lbs
0.454 kg	1 pound	≈ 0.45 kg

Volume

Metric	Standard	Approximate
1 liter	33.8 fl oz	≈ 1.06 quarts
3.785 liters	1 gallon	≈ 3.8 L
1 mL	0.034 fl oz	≈ 20 drops

Quick Estimation Tricks

💡 Handy approximations:
• A meter is about a yard (actually 10% longer)
• A kilogram is about 2 pounds
• A liter is about a quart
• A kilometer is about 0.6 miles (multiply km by 0.6 for miles)

🎯 Practice Problems

1. Convert 10 km to miles. (1 km ≈ 0.621 mi)

A) 3.1 miles

B) 6.21 miles

C) 16.1 miles

D) 62.1 miles

2. Convert 5 pounds to kilograms. (1 lb ≈ 0.454 kg)

A) 2.27 kg

B) 11.02 kg

C) 0.91 kg

D) 5.45 kg

3. Convert 2 liters to fluid ounces. (1 L ≈ 33.8 fl oz)

A) 16.9 fl oz

B) 33.8 fl oz

C) 67.6 fl oz

D) 135.2 fl oz

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🎯 Bonus Practice

1. Your height is 6 feet (72 inches). Approximately how many cm is that? (1 in = 2.54 cm)

A) 144 cm

B) 155 cm

C) 183 cm

D) 210 cm

2. A European recipe calls for 250g of flour. About how many ounces? (1 oz ≈ 28.35 g)

A) 4.4 oz

B) 8.8 oz

C) 14 oz

D) 71 oz

3. A marathon is 42.195 km. How many miles? (1 km ≈ 0.621 mi)

A) 21.1 miles

B) 26.2 miles

C) 42.2 miles

D) 67.9 miles

4. Convert 3 gallons to liters. (1 gal ≈ 3.785 L)

A) 0.79 L

B) 7.57 L

C) 11.36 L

D) 15.14 L

5. A sign says the speed limit is 100 km/h. What is that in mph? (1 km ≈ 0.621 mi)

A) 50 mph

B) 62 mph

C) 100 mph

D) 161 mph