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Conversion calculators

Choose the quantity first, then select its starting and target units. Physical unit conversions use defined factors; currency conversion uses a dated exchange rate that may differ from your bank’s quote.

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Avoid converting the wrong dimension

One metre is 100 centimetres, but one square metre is 10,000 square centimetres. Area factors are squared and volume factors are cubed. Similarly, a temperature difference has a different conversion from an absolute Celsius or Fahrenheit reading.

Precision is not the same as accuracy

More displayed decimals cannot improve an imprecise measurement. Preserve intermediate precision, then round to match the measurement or specification. For currency, check the displayed source and date and account for provider spreads and fees separately.

FAQ

Frequently asked questions

Are metric-to-imperial conversion factors live data? ▾
Ordinary physical unit conversions use fixed definitions. They do not require a current market feed. Currency rates are different: the rate source and date matter.
Why is currency conversion different from a bank quote? ▾
A reference exchange rate is not necessarily the retail rate offered by a bank or payment provider. Spreads, fees, timing and product-specific rates can change the amount received.
How do I avoid a square-foot versus foot error? ▾
Check the dimension before converting. Length uses a linear factor; area uses its square. Use an area or square-footage tool when measuring a floor or surface.

Sources & Methodology

This topic page helps you choose a tool. Read the individual calculator’s assumptions, source dates and limitations before relying on its estimate.

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