Formula
For linear, weight and volume units: convert the source value into the group base unit, then convert the base unit into the target unit. For temperature: Celsius = (Fahrenheit − 32) × 5 ÷ 9 and Fahrenheit = Celsius × 9 ÷ 5 + 32.
Unit Converter
Convert common length, weight, volume and temperature units with the formula, exact basis and printable conversion record kept visible.
Worked example
For 10 feet to metres: 10 × 0.3048 = 3.048 metres. For 10 US gallons to litres: 10 × 3.785411784 = 37.85411784 litres. The printable report keeps the selected units, exact basis, result and notes area together.
Professional note
Master’s Tip: use a dedicated calculator when the conversion affects material ordering, payroll, finance, temperature safety or compliance. A general unit converter is best for transparent first-pass conversion and printable recordkeeping.
Regional and unit assumptions
Standard or basis: SI decimal relationships, the international inch/foot, international avoirdupois pound and US liquid gallon. The page does not apply building-code, engineering, medical, food-safety or legal compliance tolerances.
Assumptions and limitations
- Length, weight and volume conversions stay inside their own measurement group; incompatible unit pairs are not converted.
- The calculator uses exact relationships where defined, including 1 inch = 25.4 mm, 1 ft = 0.3048 m, 1 lb = 0.45359237 kg and 1 US gallon = 3.785411784 L.
- US liquid gallons are used for gallon conversions, not imperial gallons.
- Rounding is for display only. Keep source values, formula and assumptions visible when the result is used in a quote, worksheet, drawing or job note.
Methodology & Accuracy
How this calculator is checked
CalculationTime pages are built around visible arithmetic: the formula, assumptions, worked example and practical limitations are shown so the result can be checked rather than simply trusted.
Formula used
For linear, weight and volume units: convert the source value into the group base unit, then convert the base unit into the target unit. For temperature: Celsius = (Fahrenheit − 32) × 5 ÷ 9 and Fahrenheit = Celsius × 9 ÷ 5 + 32.
Standard or basis
Standard or basis: SI decimal relationships, the international inch/foot, international avoirdupois pound and US liquid gallon. The page does not apply building-code, engineering, medical, food-safety or legal compliance tolerances.
Where a calculator follows a named legal, trade or industry standard, that standard is cited visibly. Otherwise the page uses transparent general arithmetic and states its limits.Master's Tip
Master’s Tip: use a dedicated calculator when the conversion affects material ordering, payroll, finance, temperature safety or compliance. A general unit converter is best for transparent first-pass conversion and printable recordkeeping.
Related calculators
Questions
Can one unit converter handle every unit?
A general unit converter is useful for common compatible units, but specialist calculators are better when rules, tolerances, material waste, payroll law, finance formulas or safety standards matter.
Which gallon does this calculator use?
This page uses the US liquid gallon. Imperial gallons are different and should not be mixed into fuel, cooking, pool or trade records without changing the basis.
Are inches, feet and pounds exact conversions?
The modern international inch, foot and avoirdupois pound have exact metric relationships for this type of arithmetic: 1 inch = 25.4 mm, 1 foot = 0.3048 m and 1 pound = 0.45359237 kg.
Why does the printable report matter?
A conversion result is easier to trust later when the source number, selected units, formula, assumptions, date/page context and notes area are printed together.
Can I convert temperature the same way as length?
No. Temperature uses an offset formula, not only a multiplication factor. Celsius to Fahrenheit and Fahrenheit to Celsius are handled with their own formulas.
Calculation note
A general unit converter is a bridge between measurement systems. It helps people compare product dimensions, recipe volumes, travel distances, classroom examples and job notes without hiding the conversion basis.
Compatible units matter first
A useful converter should not pretend every unit can become every other unit. Length belongs with length, mass with mass, volume with volume and temperature with temperature. Keeping the group visible prevents a quick tool from becoming a source of bad records.
Exact definitions make common conversions dependable
Many everyday imperial-to-metric relationships are fixed exactly for calculation purposes. The international inch is exactly 25.4 millimetres, the international foot is exactly 0.3048 metres and the avoirdupois pound is exactly 0.45359237 kilograms.
Printable conversion records are practical evidence
A conversion used in a quote, classroom handout, supplier note or homeowner measurement record should preserve more than the final number. The report shows inputs, formula, assumptions, page/date context and a notes area so the conversion can be checked later.
Sources and further readingNIST: SI units and metric relationshipsNIST Handbook 44 Appendix C: General Tables of Units of Measurement