Convert Grams to Tonnes - Weight Converter
This tool converts mass from grams (g) to metric tonnes (t). The metric tonne (also spelled 'tonne') equals 1,000 kilograms and 1,000,000 grams, so the conversion is a fixed mathematical relationship.
Use this converter for quick, precise unit changes when recording weights, preparing reports, or checking calculations for supply chain, laboratory, or regulatory work. See the methodology and accuracy notes below for guidance on rounding, measurement uncertainty, and traceability.
Governance
Record 18713335fc3a • Reviewed by Fidamen Standards Committee
Interactive Converter
Convert between gram and tonne with precision rounding.
Quick reference table
| Gram | Tonne |
|---|---|
| 1 g | 0 t |
| 5 g | 0 t |
| 10 g | 0 t |
| 25 g | 0 t |
| 50 g | 0.0001 t |
| 100 g | 0.0001 t |
Methodology
The conversion is based on the International System of Units (SI) definition: 1 tonne = 1,000 kilograms = 1,000,000 grams. No temperature, pressure, or material-specific correction is required for the pure unit conversion itself.
For applied work (e.g., weighing bulk materials or chemical samples) account for measurement uncertainty, balance calibration, and sample handling. Calibration traceable to national metrology institutes is recommended; follow guidance from standards organizations for documentation and uncertainty reporting.
Key takeaways
This is an exact unit conversion: 1 t = 1,000,000 g. Use division by 1,000,000 to convert grams to tonnes.
When using measured values, include calibration status and measurement uncertainty in reports. Round results to an appropriate number of significant figures for your application.
Worked examples
1000 g → 0.001 t
5000000 g → 5 t
250 g → 0.00025 t
F.A.Q.
Is the conversion exact or approximate?
The mathematical conversion between grams and metric tonnes is exact: 1 tonne = 1,000,000 grams. Any approximation arises only from rounding or from the uncertainty in measured input values.
Do I need to adjust for temperature or material density?
Not for the unit conversion itself. Temperature and density affect volume and some measurement processes, but converting mass units from grams to tonnes is independent of those factors. When converting from volume to mass, include density and temperature corrections as needed.
How many significant figures should I report?
Report results with the same number of significant figures as the least-precise measured value. For calculated conversions based on a measured mass, include the instrument's stated uncertainty and round accordingly.
What calibration or traceability should I document?
Document the balance or scale calibration certificate, calibration date, uncertainty, and traceability chain to your national metrology institute when measurements are used for compliance, invoicing, or scientific reporting.
Are there regulatory limits I should consider when reporting large masses?
Regulatory limits depend on jurisdiction and context (e.g., hazardous materials, emissions reporting). Consult relevant national and industry regulations and include measurement traceability and uncertainty when submitting figures for compliance.
Sources & citations
- NIST — SI Units and Conventions — https://www.nist.gov/pml/weights-and-measures
- ISO — Quantities and Units (ISO Catalogue) — https://www.iso.org/standards.html
- IEEE Standards Association — https://standards.ieee.org
- OSHA — Measurement and Recordkeeping — 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
- NIST SP 811 — Guide for the Use of the International System of Units — https://www.nist.gov/pml/special-publication-811
Further resources
Versioning & Change Control
Audit record (versions, QA runs, reviewer sign-off, and evidence).
Record ID: 18713335fc3aWhat changed (latest)
v1.0.0 • 2025-11-26 • 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 • 2025-11-26 • 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 26, 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 • 2025-11-26 • 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: 1d01dc8358af