Unit Converter
100% LocalConvert between units of length, weight, temperature, speed and more.
Millimeter
1 mm
Centimeter
0.1 cm
Meter
0.001 m
Kilometer
0.000001 km
Inch
0.0393701 in
Foot
0.00328084 ft
Yard
0.00109361 yd
Mile
6.213710e-7 mi
Nautical Mile
5.399570e-7 nmi
Enter a value and pick the unit category (length, weight, temperature, speed). All conversions update.
What is Unit Converter?
Frequently Asked Questions
Technical Deep Dive
Unit Converter
A comprehensive unit converter covering 10 categories: Length, Weight, Temperature, Area, Volume, Speed, Data Size, Time, Energy, and Pressure. All conversions happen client-side instantly. Shows all unit results simultaneously for easy comparison.
Two-Way Conversion
Convert in either direction with consistent semantics on the round-trip.
Type-Faithful
Preserves nulls, numbers, booleans, and structure, no string-soup translation.
Production-Sized
Built to handle real-world payloads, not just textbook examples.
01 Unit Categorization Matrix
| Category | Reference Unit | Metric Basis | Imperial Basis |
|---|---|---|---|
| Length | Meter (m) | km, m, cm, mm | mile, yard, foot, inch |
| Weight | Gram (g) | kg, g, mg | ton, lb, oz, stone |
| Energy | Joule (J) | kJ, Calorie | kWh, BTU |
| Data | Byte (B) | KB, MB, GB | KiB, MiB, GiB |
| Pressure | Pascal (Pa) | bar, atm, mmHg | psi |
02 Conversion Pipeline
03 Real-World Use Cases
A unit converter sits between everyday cooking and SI-vs-IEC engineering arguments. These are the conversions that actually save time across kitchens, shipping labels, and CI logs.
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Recipe scaling across regions US cups, UK imperial pints, and metric grams don't line up cleanly, a US gallon is 3.785 L, a UK gallon is 4.546 L (20% off). Convert before you halve the batter.
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International shipping (lb ↔ kg) Carrier quotes flip between kilograms and pounds depending on the lane. 1 kg = 2.20462 lb. Customs forms reject "approximately", round to the gram the carrier expects.
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Engineering: psi ↔ bar ↔ kPa Tire pressure (psi), brewing/HVAC (bar), datasheets (kPa). 1 bar ≈ 14.504 psi ≈ 100 kPa. Plus or minus 1% across the board, close enough for tires, not for a pressure vessel spec.
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Code-time MB vs MiB The classic CI bug: a 100 MB limit check fails on a 96 MiB file (which is 100,663,296 bytes). IEC 80000-13 says MiB = 2^20 bytes, MB = 10^6 bytes. Pick one and label it.
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Time units in logs and SLAs "99.9% uptime" is 8h 45m of downtime per year, 43m 12s per month, 1m 26s per day. Convert percentages to wall-clock minutes before you write the SLA.
04 Worked Examples
1 TB = 1,000,000,000,000 bytes (10^12)1,000,000,000,000 / 1024^3 = 931.32 GiBDisk vendors advertise the decimal number; operating systems divide by 1024^3. Per IEC 80000-13 the OS unit is properly GiB (gibibyte). No data was lost, the drive is genuinely 1 TB; it's also 931 GiB. Two labels for the same bytes.
°F = °C × 9/5 + 32
K = °C + 273.15
-40 °C = -40 °F = 233.15 K-40 is the one point where Celsius and Fahrenheit numerically coincide, useful for sanity-checking a formula. Note temperature is an affine scale, not linear: 20 °C is not "twice as hot" as 10 °C.
Wheel lug nuts: 120 N·m120 N·m × 0.737562 = 88.5 ft·lbConversion factor: 1 N·m = 0.737562 ft·lb. Don't confuse with the unrelated "lb-ft" inversion seen on some imperial torque wrenches; both are equivalent. Click-type wrenches drift over time, so 5% slack is the practical tolerance.
05 Related Tools
Conversion is rarely a standalone task, these pair well when the values you're converting are timestamps, token counts, or model-cost comparisons.
Timestamp Converter
Convert Unix epoch seconds/milliseconds to ISO 8601 and back across time zones, the time-unit cousin of this tool.
LLM Token Counter
When the "unit" you care about is tokens, not bytes, counts characters, words, and provider-specific token estimates.
LLM Model Comparison
Compare context windows, prices per million tokens, and limits side-by-side across providers, apples to apples.