What does the unit conversion checker produce?
Convert supported physical units and check reported conversions with exact factors, visible formulas and customer-entered tolerances.
The working area above runs the supported validator in the browser. It keeps the result inspectable and preserves every unresolved item for responsible review.
What do you need before you start?
- A named owner has defined the task and the organization’s intended use.
- The customer has authority to use every supplied record, source or connection.
- Prepare the result in this browser and resolve visible input errors before exporting.
What information do you enter?
Prepare only the bounded inputs listed below for this validator.
- A CSV, XLSX or dataset JSON file with one reference, source value, source unit and target unit per row.
- An optional reported converted value and optional absolute tolerance in target units. A blank tolerance means zero.
- Exact case-sensitive symbols from the supported list. Choose US liquid units explicitly.
| Field | What to enter | Fictional example |
|---|---|---|
| Record referenceRequired | Use a unique record reference for each conversion. | FICTIONAL-VOLUME |
| Source valueRequired | Enter a decimal or scientific number with at most 40 digits and an exponent from -40 through 40. | 1 |
| Source unitRequired | Use an exact supported case-sensitive symbol, such as US gal. | US gal |
| Target unitRequired | Choose a supported unit measuring the same quantity. | L |
| Reported converted valueOptional | Enter the value you want checked, or leave it blank for calculation only. | 3.785411784 |
| Absolute tolerance in target unitsOptional | Enter a nonnegative absolute tolerance in target units. A blank value means zero. | 0 |
What you can download
Every result must identify its supplied facts, assumptions and unresolved items.
| Free result | Included downloads |
|---|---|
Enter your information, inspect the on-screen result and keep a browser backup. Editing and direct copies of your entered information stay free. |
These supported outputs are free. No checkout is required. |
Fictional conversion summary (PDF). Fictional finalized pack (ZIP). Fictional input dataset (JSON). Requires tailoring and responsible review. Samples use the finalized pack renderer.
How does the unit conversion checker work?
- 1Prepare the source dataset
Give each conversion a unique reference. Keep decimal points and exact unit symbols. Up to 5,000 rows are supported.
- 2Choose units and tolerance
Use supported units within the same quantity. Enter a reported value to check it. Set an absolute tolerance in target units or leave it blank for zero.
- 3Convert and inspect
Review calculated values, exact fractions, formulas and every unresolved row. Calculated-only rows have no accuracy check.
- 4Keep the reviewed result
Download complete JSON or CSV results free. The finalized pack contains an Excel report, original review dataset and PDF summary.
Method and sources
Apply the steps above to the supported inputs. Use the listed source sections to review the rule basis, assumptions and limits.
- Handbook 44 (2023), Appendix CExact international length, avoirdupois mass, metric and US liquid volume definitions, and absolute temperature equations. C-3 through C-7, C-19 through C-23 and C-27.National Institute of Standards and Technology. Reviewed 2026-10-06.
- Guide to the SI, Appendix B.8Supported quantity dimensions and conversion relationships. Rounded table values are distinguished from exact definitions. Units of length, mass, volume, duration and temperature.National Institute of Standards and Technology. Reviewed 2026-10-06.
Common questions
What information does the unit conversion checker need?
Enter a CSV, XLSX or dataset JSON file with one reference, source value, source unit and target unit per row; an optional reported converted value and optional absolute tolerance in target units. A blank tolerance means zero; exact case-sensitive symbols from the supported list. Choose US liquid units explicitly. A named owner has defined the task and the organization’s intended use.
What does the unit conversion checker produce?
A row-level conversion report with calculated values, exact fractions, formulas and tolerance findings. Complete free JSON and CSV result downloads. Original files remain in this browser. A finalized Excel conversion report, original review dataset and PDF summary of the first 100 rows. Review unresolved findings and limitations before use.
Who makes the final decision?
A responsible person reviews the result. Convert through the dimension base using exact rational factors and offsets. Compare the unrounded result with the entered value using an absolute tolerance in target units. A blank tolerance means zero. Display at most 12 decimal places, rounding ties away from zero. Exact fractions remain in JSON, CSV and Excel.
Is this tool free?
Yes. The on-screen result and listed downloads are free. No checkout is required. Keep local backups and review the stated method and limits.
Can I use the unit conversion checker for this task?
Convert supported units and expose assumptions. Convert through the dimension base using exact rational factors and offsets. Compare the unrounded result with the entered value using an absolute tolerance in target units. A blank tolerance means zero. Display at most 12 decimal places, rounding ties away from zero. Exact fractions remain in JSON, CSV and Excel.
What still needs review?
Convert through the dimension base using exact rational factors and offsets. Compare the unrounded result with the entered value using an absolute tolerance in target units. A blank tolerance means zero. Display at most 12 decimal places, rounding ties away from zero. Exact fractions remain in JSON, CSV and Excel.
The international foot and avoirdupois mass are used. Liquid customary units require US labels. Days mean exactly 24 elapsed hours.
Temperature values are absolute, not differences. Survey feet, troy mass, Imperial liquid units, compound units and currencies remain unsupported.
Arithmetic matches do not authenticate measurements, establish measurement uncertainty or decide a legal threshold.