Convert Grams to Pounds - Weight Converter
This tool converts a mass given in grams (g) to avoirdupois pounds (lb). The conversion uses the internationally recognized definition of the avoirdupois pound relative to the kilogram, making the mathematical relationship exact.
The converter is intended for general use including lab work, shipping calculations, recipe scaling, and workplace evaluations. For decisions that depend on legal, safety, or medical limits, verify measured values and instrument calibration before relying on converted results.
Results are presented with configurable display precision; the underlying conversion factor is exact by definition, but measured input values have uncertainty that should be considered when reporting results.
Governance
Record c86f6d8f6839 • Reviewed by Fidamen Standards Committee
Interactive Converter
Convert between gram and pound with precision rounding.
Quick reference table
| Gram | Pound |
|---|---|
| 1 g | 0.0022 lb |
| 5 g | 0.011 lb |
| 10 g | 0.022 lb |
| 25 g | 0.0551 lb |
| 50 g | 0.1102 lb |
| 100 g | 0.2205 lb |
Methodology
Conversion is based on the fixed relationship that defines the avoirdupois pound in terms of the kilogram: 1 pound (lb) = 0.45359237 kilogram (kg). Since 1 kilogram = 1000 grams, 1 lb = 453.59237 grams exactly.
Because the factor 453.59237 g per lb is exact by definition, the mathematical conversion from grams to pounds is exact. Any loss of precision originates from input measurement uncertainty, numerical rounding, or display formatting.
For traceability and calibration recommendations consult national metrology guidance and standards. Instruments and scales should be calibrated per national and international standards (for example NIST and ISO guidance). Consider workplace safety thresholds (OSHA) and numerical accuracy characteristics (IEEE floating-point considerations) when using converted values in regulated contexts.
Key takeaways
Use pounds = grams / 453.59237 for exact mathematical conversion between grams and avoirdupois pounds.
Remember that while the conversion factor is exact, real-world measured inputs have uncertainty; display rounding should reflect that uncertainty.
For regulated or safety-critical uses, ensure measurements and conversions are traceable and compliant with relevant NIST, ISO, IEEE, or OSHA guidance.
Worked examples
100 g → 100 / 453.59237 = 0.220462262 lb (round to 0.22046 lb for 5 decimal places).
500 g → 500 / 453.59237 = 1.1023113109999999 lb (round to 1.10231 lb).
1 g → 1 / 453.59237 = 0.002204622622 lb (commonly shown as 0.00220462 lb).
F.A.Q.
Is the conversion factor exact?
Yes. The avoirdupois pound is defined such that 1 lb = 0.45359237 kg exactly, and 1 kg = 1000 g exactly, so 1 lb = 453.59237 g is an exact definition. Any imprecision in results comes from the measured input and rounding.
Why do results sometimes show rounding differences?
Display rounding and numerical precision can produce visible differences. Use a number of decimal places that matches the measurement instrument's accuracy. For example, a kitchen scale with 1 g resolution does not justify showing 8 decimal places in pounds.
Which pound is used here? Are there different pounds?
This converter uses the international avoirdupois pound, which is standard for most everyday and commercial uses. Other historical systems (for example troy or apothecaries' pounds) are different and are not used here.
How should I account for measurement uncertainty?
Report the measured value with its instrument uncertainty or resolution, then convert. Do not imply greater precision after conversion than existed in the original measurement. For traceable measurements follow calibration procedures per national metrology guidance.
Do workplace safety or legal limits change the conversion?
No. The conversion itself is mathematical and unchanged, but when using converted values for compliance, safety, or legal purposes confirm that measurements, rounding, and calibrations meet the relevant regulatory or industry standard requirements (for example OSHA or applicable ISO standards).
Sources & citations
- NIST Special Publication - Guide for the Use of the International System of Units (SI) — https://www.nist.gov/pml/special-publication-811
- NIST - Weights and Measures / Mass and Related Quantities — https://www.nist.gov/pml/weights-and-measures
- International Organization for Standardization (ISO) — https://www.iso.org
- IEEE Standards Association — https://standards.ieee.org
- Occupational Safety and Health Administration (OSHA) — https://www.osha.gov
- ISO 80000-4:2019 — Mechanics — https://www.iso.org/standard/64975.html
- BIPM SI Brochure (9th edition, 2019) — https://www.bipm.org/en/publications/si-brochure
Further resources
Related tools
Versioning & Change Control
Audit record (versions, QA runs, reviewer sign-off, and evidence).
Record ID: c86f6d8f6839What changed (latest)
v1.0.0 • 2025-11-17 • MINOR
Initial publication and governance baseline.
Why: Published with reviewed formulas, unit definitions, and UX controls.
Public QA status
PASS — golden 25 + edge 120
Last run: 2026-01-23 • Run: golden-edge-2026-01-23
Versioning & Change Control
Audit record (versions, QA runs, reviewer sign-off, and evidence).
What changed (latest)
v1.0.0 • 2025-11-17 • MINOR
Initial publication and governance baseline.
Why: Published with reviewed formulas, unit definitions, and UX controls.
Public QA status
PASS — golden 25 + edge 120
Last run: 2026-01-23 • Run: golden-edge-2026-01-23
Engine
v1.0.0
Data
Baseline (no external datasets)
Content
v1.0.0
UI
v1.0.0
Governance
Last updated: Nov 17, 2025
Reviewed by: Fidamen Standards Committee (Review board)
Credentials: Internal QA
Risk level: low
Reviewer profile (entity)
Fidamen Standards Committee
Review board
Internal QA
Entity ID: https://fidamen.com/reviewers/fidamen-standards-committee#person
Semantic versioning
- MAJOR: Calculation outputs can change for the same inputs (formula, rounding policy, assumptions).
- MINOR: New features or fields that do not change existing outputs for the same inputs.
- PATCH: Bug fixes, copy edits, or accessibility changes that do not change intended outputs except for previously incorrect cases.
Review protocol
- Verify formulas and unit definitions against primary standards or datasets.
- Run golden-case regression suite and edge-case suite.
- Record reviewer sign-off with credentials and scope.
- Document assumptions, limitations, and jurisdiction applicability.
Assumptions & limitations
- Uses exact unit definitions from the Fidamen conversion library.
- Internal calculations use double precision; display rounding follows the unit's configured decimal places.
- Not a substitute for calibrated instruments in regulated contexts.
- Jurisdiction-specific rules may require official guidance.
Change log
v1.0.0 • 2025-11-17 • MINOR
Initial publication and governance baseline.
Why: Published with reviewed formulas, unit definitions, and UX controls.
Areas: engine, content, ui • Reviewer: Fidamen Standards Committee • Entry ID: ec5b405ef64d