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)
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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
Check your answers with the tools
Grade & standards alignment
These unit conversion worksheets target the Grades 4–5 band of the Common Core State Standards for Mathematics (CCSSM). The relevant CCSS math domains are:
Source: Common Core State Standards for Mathematics (2010). National Governors Association Center for Best Practices (NGA Center) & Council of Chief State School Officers (CCSSO). Retrieved 2026-08-11 from https://www.corestandards.org/Math/.
The CCSSM are public, open-license standards; this alignment is provided for planning and is not an official endorsement by the standards authors.
How these worksheets are built (accuracy & trust)
- •Problems are generated by a deterministic engine using exact integer and rational arithmetic — answers are reduced to lowest terms and never rely on floating-point rounding, so they match the matching UnitFig converter.
- •Grade presets follow the CCSSM progression above; pick a grade to get age-appropriate number ranges.
- •Content is reviewed for accuracy and refreshed each year (2026). Worksheet copy and examples are original and written for classroom use.
Safe for classrooms — zero data collection
UnitFig collects no personal information from children or any visitor. Worksheets run entirely in the browser: no account, no name or email, and student answers never leave the device. We follow a COPPA-aligned, zero-collection design so teachers and parents can use these sheets without a signup wall or privacy concern. See our Privacy Policy.
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.
More worksheets
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.