Which conversion categories are included?
The single converter covers common length, area, volume, weight or mass, temperature, speed, time, and data storage units. It intentionally does not create a separate page for every pair.
Common Units calculator
Unit Converter
Convert common length, area, volume, mass, temperature, speed, time, and data storage units, then reuse the result without mixing unit systems.
Interactive converter
Convert a common measurement
Choose one category so only relevant units appear. Use a preset for a common pair or keep full manual control.
What to do next
Continue your decision
Formula, example, assumptions, and FAQs — open any section for the detail.
Formula
Linear unit conversion
Converted value = entered value × source-to-base factor ÷ target-to-base factorLength, area, volume, mass, speed, time, and data units use a deterministic base-unit table. For example, 1 foot is exactly 0.3048 metre and 1 square foot is exactly 0.09290304 square metre.
Temperature conversion
°F = (°C × 9/5) + 32 · °C = (°F − 32) × 5/9 · K = °C + 273.15Temperature scales have different zero points, so they use offset formulas rather than a single multiplication factor. Inputs below absolute zero are rejected.
Decimal and binary data storage
1 KB = 1,000 B · 1 MB = 1,000,000 B · 1 KiB = 1,024 B · 1 MiB = 1,048,576 BKB, MB, GB, and TB are decimal units. KiB, MiB, GiB, and TiB are binary units. They are deliberately kept separate because 1 GB is not 1 GiB.
Month and year estimates
1 month estimate = 30 days · 1 year estimate = 365 daysThese fixed durations are useful for rough planning only. Use exact calendar dates for birthdays, billing periods, deadlines, leap years, or date differences.
Worked example
Example: 10 feet to metres for a room
A room side is measured as 10 feet, but a paint plan or construction drawing uses metres.
Calculation:10 ft × 0.3048 metre per foot = 3.048 metres.
Result:10 feet is 3.048 metres. Convert every room dimension to the same unit system, continue to Area Calculator for the surface measurement, then use the relevant material calculator.
Assumptions
- Linear conversions use the fixed factors shown by the calculator and do not call an external service.
- Inch, foot, yard, and mile use international definitions based on exactly 1 inch = 0.0254 metre.
- US teaspoon, tablespoon, cup, fluid ounce, and gallon use US customary liquid definitions; UK gallon is a separate unit.
- Mass ounces and pounds are avoirdupois units, not troy weight or fluid volume.
- Temperature values are physically valid only at or above absolute zero.
- Speed units are treated as exact distance-per-time ratios.
- Day means 24 hours and week means 7 days in fixed-duration conversions.
- Month estimate means 30 days and year estimate means 365 days; neither is an exact calendar period.
- Decimal data units use powers of 1,000 and binary data units use powers of 1,024.
- Displayed precision changes rounding only; it does not make a source measurement more accurate.
Common mistakes
- Mixing feet and metres across room dimensions before calculating paint, tile, flooring, or construction quantities.
- Using a length conversion for an area: square feet and feet are not the same thing.
- Treating US gallon and UK gallon as equal.
- Assuming every cup, teaspoon, or tablespoon standard is identical; this tool labels and uses US customary kitchen volumes.
- Confusing ounces of mass with US fluid ounces of volume.
- Multiplying temperature by a factor without applying the Celsius or Fahrenheit offset.
- Treating a 30-day month or 365-day year estimate as an exact date difference.
- Treating GB and GiB as equal when comparing drive, memory, cloud, or operating-system figures.
- Adding decimal places to a result and assuming the original measurement became more precise.
Accuracy notes
Conversion factors and temperature formulas are deterministic, and the result is rounded only for the selected display precision. Exact factors do not correct an imprecise source measurement. Kitchen measures depend on the stated US customary standard, and month or year duration results are explicitly estimates.
Frequently asked questions
Can I use it for Indian and international measurements?
Yes. Common Indian and global tasks include feet to metres for rooms, sq ft to sq m for property, litres to gallons for fuel or paint, kg to pounds, Celsius to Fahrenheit, and kilometres to miles. Keep every input in one unit system when a later calculator combines measurements.
Why are square feet and feet in different categories?
Foot is a length unit. Square foot is an area unit. A 10 ft by 10 ft room has a 100 sq ft floor, so area conversions use squared factors rather than ordinary length factors.
Are US and UK gallons the same?
No. A US gallon is exactly 3.785411784 litres, while a UK imperial gallon is exactly 4.54609 litres. Select the gallon named by the source.
What kitchen cup standard does this converter use?
It uses the US customary cup of 236.5882365 mL, with matching US teaspoon and tablespoon values. Metric cups and other local recipe standards can differ, so check the recipe source.
Why can temperature not use one conversion factor?
Celsius, Fahrenheit, and Kelvin have different zero points. Their formulas need an offset as well as a scale change. Kelvin below zero and equivalent temperatures below absolute zero are invalid.
Why are month and year results marked as estimates?
Calendar months have different lengths and leap years have 366 days. This converter uses 30 days per month estimate and 365 days per year estimate. Use Age & Date Difference Calculator when exact dates matter.
What is the difference between GB and GiB?
GB is decimal: 1 GB equals 1,000,000,000 bytes. GiB is binary: 1 GiB equals 1,073,741,824 bytes. Device makers, operating systems, and software may display these conventions differently.
Does choosing six decimals make the result more accurate?
No. It shows more calculated digits. Real accuracy still depends on the source measurement, instrument, product label, and whether the selected unit standard matches the source.
This converter is for everyday measurement and planning. It does not certify instruments, replace engineering or laboratory standards, provide medical dosing guidance, or claim scientific precision beyond the entered value and stated unit definitions. Verify safety-critical, regulated, or contractual measurements with the applicable standard.Read the full disclaimer.