Unit Conversion Factors: A Verified Reference

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The full dataset is available as a machine readable JSON file. Records use a fixed schema with from_unit, to_unit, factor, formula_note, is_exact, source_url, source_name and last_verified.

File: unit-conversions-2026-v1.json · CC-BY-4.0 license terms

How to cite

Gizmoop Editorial Team (2026). Unit Conversion Factors: A Verified Reference (2026 Edition, v1.0). https://gizmoop.com/research/unit-conversions

Categories in this dataset

• Length and distance (25 records)
• Mass and weight (20 records)
• Volume (22 records)
• Area (19 records)
• Temperature (7 records)
• Speed and velocity (12 records)
• Energy (12 records)
• Power (9 records)
• Pressure (14 records)
• Time (13 records)
• Data storage (12 records)

Methodology

How conversion factors were sourced

The primary source for SI and imperial conversion factors is the United States National Institute of Standards and Technology (NIST), specifically the Reference on Constants, Units, and Uncertainty. Exact factors (such as 1 inch = 2.54 cm, 1 lb = 0.45359237 kg) are reproduced from the international yard and pound agreement of 1959 as adopted by NIST. Non-exact factors are listed at the precision published by NIST or by the originating standards body (IAU for astronomical units, IEC 80000-13 for binary data prefixes, IEEE 1541 for bit and byte definitions).

Regional and traditional units

For South Asian land and weight units (marla, kanal, bigha, tola, ser, maund), the dataset cites the established trade and land-measurement standards used in Pakistan and India. These units are not officially defined by NIST but have stable, widely accepted conversion factors used in courts, land registries, and bullion markets. Where regional values vary by jurisdiction (the bigha is one example), the dataset notes the variant explicitly.

Exact vs rounded

The is_exact column distinguishes factors that are exact by definition (for example, 1 ft = 0.3048 m, by the 1959 international agreement) from those rounded for display (for example, 1 kg = 2.20462 lb, where the true value has more decimal places). When using a rounded factor for high-precision work, refer to the formula in formula_note for the exact computation.

Inclusion criteria

Factors are included if at least one of the following holds: it is a recognised SI or imperial unit; it appears in NIST reference tables; it is in common use in commerce, science, engineering, or daily life in any major region; or it is a standardised unit (IEC, ISO, IEEE, IAU). Niche historical units that are no longer in active use are excluded.

Update cadence

The dataset is reviewed quarterly at minimum. SI and imperial factors are stable for decades; the most frequent update target is the regional South Asian unit set as customs and land authorities sometimes publish revised reference values.

Versioning policy

We use semantic versioning. v1.x releases add records and refine notes. v2.x releases would change the record schema in a breaking way. The dataset identifier (unit-conversions-2026-v1) is stable for the v1 series.

Citation guidelines

You may reuse this dataset in any context, commercial or non commercial, with attribution to Gizmoop. The recommended citation forms are below.

APA

Gizmoop Editorial Team. (2026). Unit Conversion Factors: A Verified Reference (2026 Edition, v1.0) [Dataset]. Gizmoop. https://gizmoop.com/research/unit-conversions

MLA

Gizmoop Editorial Team. "Unit Conversion Factors: A Verified Reference (2026 Edition, v1.0)." Gizmoop, 3 June 2026, gizmoop.com/research/unit-conversions.

BibTeX

@misc{gizmoop_unitconversions_2026,
  title  = {Unit Conversion Factors: A Verified Reference (2026 Edition, v1.0)},
  author = {{Gizmoop Editorial Team}},
  year   = {2026},
  url    = {https://gizmoop.com/research/unit-conversions},
  note   = {Dataset, CC-BY-4.0}
}

If you use this dataset in a research paper, blog post, presentation, or product, please email gizmoopofficial@gmail.com so we can link to your work.

Changelog

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