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Unit Conversion Practice Worksheets — US ↔ Metric

Unit conversion is the bridge between the US customary system and the metric system — and the most valuable worksheet topic on UnitFig because it ties directly to the site's converters. Every answer is computed with the exact NIST / SI constant (1 lb = 0.45359237 kg, 1 in = 2.54 cm…), so students can verify any answer against the matching UnitFig converter and see the step by step. This is the only worksheet set on the web that pairs conversion practice with a real converter on the same site.

Sample problems (new ones below)

73 in = ? cm → 185.42 cm48 mph = ? km/h → 77.25 km/h84 mph = ? km/h → 135.18 km/h29 mi = ? km → 46.671 km2 ft = ? m → 0.610 m60 gal = ? L → 227.12 L2 lb = ? kg → 0.907 kg94 kg = ? lb → 207.23 lb67 gal = ? L → 253.62 L19 kg = ? lb → 41.89 lb20 ft = ? m → 6.096 m26 in = ? cm → 66.04 cm49 ft = ? m → 14.935 m86 lb = ? kg → 39.009 kg74 ft = ? m → 22.555 m35 mi = ? km → 56.327 km89 gal = ? L → 336.90 L89 lb = ? kg → 40.370 kg91 mi = ? km → 146.450 km9 lb = ? kg → 4.082 kg84 ft = ? m → 25.603 m7 mi = ? km → 11.265 km29 kg = ? lb → 63.93 lb41 ft = ? m → 12.497 m

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Unit Conversion Practice
Name: _______________  ·  Date: _______________
unitfig.com/math-worksheets/unit-conversion · free printable
1.12 kg = ? lb
2.73 lb = ? kg
3.98 ft = ? m
4.29 mi = ? km
5.69 in = ? cm
6.22 in = ? cm
7.92 lb = ? kg
8.11 mph = ? km/h
9.48 ft = ? m
10.39 lb = ? kg
11.75 in = ? cm
12.59 lb = ? kg
13.40 mi = ? km
14.55 lb = ? kg
15.50 kg = ? lb
16.71 in = ? cm
17.48 gal = ? L
18.46 in = ? cm
19.91 kg = ? lb
20.82 gal = ? L
21.49 ft = ? m
22.63 gal = ? L
23.71 gal = ? L
24.38 mi = ? km
Answer Key
1. 26.46 lb(kilograms to pounds: 1 kg = 2.2046226218 lb (exact NIST/SI constant))
2. 33.112 kg(pounds to kilograms: 1 lb = 0.45359237 kg (exact NIST/SI constant))
3. 29.870 m(feet to meters: 1 ft = 0.3048 m (exact NIST/SI constant))
4. 46.671 km(miles to kilometers: 1 mi = 1.609344 km (exact NIST/SI constant))
5. 175.26 cm(inches to centimeters: 1 in = 2.54 cm (exact NIST/SI constant))
6. 55.88 cm(inches to centimeters: 1 in = 2.54 cm (exact NIST/SI constant))
7. 41.730 kg(pounds to kilograms: 1 lb = 0.45359237 kg (exact NIST/SI constant))
8. 17.70 km/h(mph to km/h: 1 mph = 1.609344 km/h (exact NIST/SI constant))
9. 14.630 m(feet to meters: 1 ft = 0.3048 m (exact NIST/SI constant))
10. 17.690 kg(pounds to kilograms: 1 lb = 0.45359237 kg (exact NIST/SI constant))
11. 190.50 cm(inches to centimeters: 1 in = 2.54 cm (exact NIST/SI constant))
12. 26.762 kg(pounds to kilograms: 1 lb = 0.45359237 kg (exact NIST/SI constant))
13. 64.374 km(miles to kilometers: 1 mi = 1.609344 km (exact NIST/SI constant))
14. 24.948 kg(pounds to kilograms: 1 lb = 0.45359237 kg (exact NIST/SI constant))
15. 110.23 lb(kilograms to pounds: 1 kg = 2.2046226218 lb (exact NIST/SI constant))
16. 180.34 cm(inches to centimeters: 1 in = 2.54 cm (exact NIST/SI constant))
17. 181.70 L(US gallons to liters: 1 gal = 3.785411784 L (exact NIST/SI constant))
18. 116.84 cm(inches to centimeters: 1 in = 2.54 cm (exact NIST/SI constant))
19. 200.62 lb(kilograms to pounds: 1 kg = 2.2046226218 lb (exact NIST/SI constant))
20. 310.40 L(US gallons to liters: 1 gal = 3.785411784 L (exact NIST/SI constant))
21. 14.935 m(feet to meters: 1 ft = 0.3048 m (exact NIST/SI constant))
22. 238.48 L(US gallons to liters: 1 gal = 3.785411784 L (exact NIST/SI constant))
23. 268.76 L(US gallons to liters: 1 gal = 3.785411784 L (exact NIST/SI constant))
24. 61.155 km(miles to kilometers: 1 mi = 1.609344 km (exact NIST/SI constant))

Teaching tips for unit conversion

  • •Learn the exact constants for the most common pairs (lb↔kg, in↔cm, ft↔m, gal↔L) — these appear constantly in science class and everyday life.
  • •Estimate before converting: 1 kg is about 2.2 lb, 1 m is a bit more than 3 ft, 1 L is about a quarter gallon. A sane estimate catches decimal-point errors.
  • •For each problem, write the unit factor as a fraction (1 lb / 0.4536 kg) and cancel units — the technique that makes conversion automatic in science courses.

Common mistakes to watch for

✗ Multiplying when you should divide (converting the wrong direction).
✓ Check the target: pounds to kilograms divides by 2.2046; kilograms to pounds multiplies. Ask "will the number get bigger or smaller?" before computing.
✗ Using a rounded constant and getting a slightly different answer than the key.
✓ The engine uses exact constants. Use the exact values in your own work, or verify with the UnitFig converter which applies the same constants.

Check your answers with the tools

Browse all converters →Quick conversion charts →

Frequently Asked Questions

Are these answers the same as the UnitFig converters?

Yes — the worksheet engine imports the exact NIST / SI constants and applies the same formulas as the site's converters, so a student can check any answer with the matching tool.

What units are covered?

Pounds↔kilograms, feet↔meters, inches↔centimeters, miles↔kilometers, US gallons↔liters, and mph↔km/h — the most common US↔metric pairs.

What grade is unit conversion taught?

Measurement conversion appears in grade 4–5 (4.MD.A.1, 5.MD.A.1) and metric units are used throughout middle school science.

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Last Updated 2026 | Problems are algorithm-generated with the exact NIST/SI constants used by UnitFig converters. Answers are computed programmatically and can be verified with the matching converter.