Unit Reference Tables
Quick-reference conversion factors and benchmarks for common unit systems. All values are exact or rounded to 6 significant figures.
Weight & Mass
Conversion factors between kilogram, pound, ounce, tonne, and stone.
| Unit | Grams (g) | Pounds (lb) | Ounces (oz) | Tonnes (t) |
|---|---|---|---|---|
| 1 kilogram (kg) | 1,000 | 2.20462 | 35.274 | 0.001 |
| 1 pound (lb) | 453.592 | 1 | 16 | 0.000454 |
| 1 ounce (oz) | 28.3495 | 0.0625 | 1 | 0.0000284 |
| 1 tonne (t) | 1,000,000 | 2,204.62 | 35,274 | 1 |
| 1 stone (st) | 6,350.29 | 14 | 224 | 0.00635 |
Length
Conversion factors between metre, foot, inch, kilometre, and mile.
| Unit | mm | cm | Feet | Inches | Miles |
|---|---|---|---|---|---|
| 1 metre (m) | 1,000 | 100 | 3.28084 | 39.3701 | 0.000621 |
| 1 foot (ft) | 304.8 | 30.48 | 1 | 12 | 0.000189 |
| 1 inch (in) | 25.4 | 2.54 | 0.0833 | 1 | 0.0000158 |
| 1 kilometre (km) | 1,000,000 | 100,000 | 3,280.84 | 39,370.1 | 0.621371 |
| 1 mile (mi) | 1,609,344 | 160,934 | 5,280 | 63,360 | 1 |
Temperature Benchmarks
Key reference temperatures across Celsius, Fahrenheit, and Kelvin scales.
| Reference Point | °C | °F | K |
|---|---|---|---|
| Absolute zero | −273.15 | −459.67 | 0 |
| Water freezes | 0 | 32 | 273.15 |
| Normal body temp | 37 | 98.6 | 310.15 |
| Water boils | 100 | 212 | 373.15 |
| Equal point | −40 | −40 | 233.15 |
Pressure
Conversion factors between atmosphere, bar, PSI, and kilopascal.
| Unit | Bar | PSI | kPa | mmHg |
|---|---|---|---|---|
| 1 atmosphere (atm) | 1.01325 | 14.6959 | 101.325 | 760 |
| 1 bar | 1 | 14.5038 | 100 | 750.062 |
| 1 PSI | 0.068948 | 1 | 6.89476 | 51.7149 |
| 1 kPa | 0.01 | 0.145038 | 1 | 7.50062 |
Data Size (Binary vs. Decimal)
Binary prefixes (IEC standard) vs. decimal prefixes (SI standard) — the source of the "why does my 1 TB drive show 931 GB?" discrepancy.
| Prefix | Binary (IEC) | Decimal (SI) | Bytes |
|---|---|---|---|
| Byte (B) | 1 B | 1 B | 1 |
| Kilobyte | 1 KiB = 1,024 B | 1 KB = 1,000 B | 1,024 / 1,000 |
| Megabyte | 1 MiB = 1,048,576 B | 1 MB = 1,000,000 B | 1,048,576 / 1,000,000 |
| Gigabyte | 1 GiB = 1,073,741,824 B | 1 GB = 1,000,000,000 B | ~1.074 billion / 1 billion |
| Terabyte | 1 TiB ≈ 1.0995 TB | 1 TB = 10¹² B | ~9.5% larger than decimal |
SI Prefixes
The International System of Units (SI) uses these prefixes for all base units. Memorising them unlocks any metric conversion.
| Prefix | Power of 10 | Example |
|---|---|---|
| tera (T) | 10¹² | 1 THz = 1 trillion Hz |
| giga (G) | 10⁹ | 1 GHz = 1 billion Hz |
| mega (M) | 10⁶ | 1 MW = 1 million watts |
| kilo (k) | 10³ | 1 km = 1,000 metres |
| hecto (h) | 10² | 1 hPa = 100 pascals |
| deca (da) | 10¹ | 1 dam = 10 metres |
| (base unit) | 10⁰ | metre, gram, second… |
| deci (d) | 10⁻¹ | 1 dl = 0.1 litres |
| centi (c) | 10⁻² | 1 cm = 0.01 metres |
| milli (m) | 10⁻³ | 1 mm = 0.001 metres |
| micro (μ) | 10⁻⁶ | 1 μm = 0.000001 metres |
| nano (n) | 10⁻⁹ | 1 ns = 0.000000001 seconds |
Cite this page
If you use these tables in an article or resource, you’re welcome to link to this page.
UnitFormula. “Unit Reference Tables.” unitformula.com/reference. Accessed 2026.