Decode any 4-band resistor color code instantly.
Each color band represents a digit or multiplier.
The 4th band indicates tolerance: gold=±5%, silver=±10%.
This tool is most useful when working from known parameters toward an unknown output — the standard direction of engineering calculation. Enter measured or specified values to get the derived result.
A frequent mistake is using nominal or rated values when actual measured values are required. Calculations based on nominal dimensions or catalogue specifications may not match field conditions — always use measured values where precision matters.
A mechanical engineer verifies a beam's deflection under a specified load using standard formulas. Running the calculation with exact dimensions confirms the design meets deflection limits before fabrication — catching an issue that would be expensive to correct in the field.
Read bands 1-2 as digits, band 3 as multiplier, band 4 as tolerance.
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