Read resistor color bands as ohms with tolerance, or turn a value into colors, with a drawing and the nearest E-series value.
To read a resistor, match the first bands to digits, the next band to a multiplier and the last band to a tolerance: yellow, violet, red, gold is 47 × 100 = 4,700 Ω, or 4.7 kΩ, with a tolerance of ±5%. A 3-band resistor has two digits and a multiplier, and its tolerance is taken as 20%. A 4-band resistor adds the tolerance band. A 5-band resistor has three digits, then the multiplier and tolerance, so brown, black, black, red, brown is 100 × 100 = 10 kΩ at ±1%. A 6-band resistor adds a band for the temperature coefficient, in ppm per kelvin: red means 50 ppm/K. Digits run black 0, brown 1, red 2, orange 3, yellow 4, green 5, blue 6, violet 7, grey 8, white 9. The multiplier is 10 to the power of the digit, plus gold for × 0.1, silver for × 0.01 and pink for × 0.001.
The tolerance says how far a real part may sit from its marked value. A 4.7 kΩ resistor at ±5% can measure anywhere from 4.465 kΩ to 4.935 kΩ, and the page prints that range. In value mode, the nearest standard value comes from the E series you pick. Standard values are spaced evenly on a log scale: E6 has 6 values per decade (typically ±20%), E12 has 12 (±10%), E24 has 24 (±5%), E48 has 48 (±2%), E96 has 96 (±1%) and E192 has 192 (typically ±0.5% and tighter). 4.8 kΩ is not a standard E24 value, and the nearest is 4.7 kΩ. In color mode the page also tells you which E series contain the value. 4.99 kΩ, for example, is an E96 value and needs 5 bands because it has three digits.
Type a value such as 330, 4.7k, 1M or 4k7 (the letter takes the place of the decimal point). The page converts it to digits and a multiplier: 330 Ω is orange, orange, brown, and 4.7 kΩ is yellow, violet, red. If the value has more digits than the bands can hold, such as 4.99 kΩ on 4 bands, the colors show the nearest value that fits and the page says so. Switch to 5 bands for three digits. Read from the end where the bands sit closer together. The tolerance band is last, and it is usually gold or silver on 4-band parts. If the bands are evenly spaced or the colors are faded, read the value with a meter instead.
The color table follows the usual IEC 60062 style set; the sources are listed in the data notes. Manufacturers do deviate from it, so treat the page as a reading aid and not a guarantee. Tolerance colors for orange, yellow and grey are left out because sources disagree on them, and so are other manufacturer-specific colours. Surface-mount parts use printed digit codes, not colors, and this page does not read those. Chip colors fade and look different under warm light, so the drawing is for orientation and the words in the result and table are what to rely on. The result is an estimate of the marked value, not a measured one.
Use the first two bands as digits, the third as the multiplier and the fourth as the tolerance. Yellow, violet, red, gold is 47 × 100 = 4,700 Ω, ±5%. Pick the colors in Colors to value mode to check any band set.
It has three digit bands, then a multiplier and a tolerance. Brown, black, black, red, brown is 100 × 100 = 10 kΩ at ±1%. The extra digit allows values such as 4.99 kΩ that a 4-band part cannot show.
The temperature coefficient, in ppm per kelvin. Brown is 100, red is 50, blue is 10 and violet is 5 ppm/K in this table. A 10 kΩ part at 50 ppm/K changes by about 0.5 Ω for a 1 K change.
Choose Value to colors and type 4.7k or 4k7. With 4 bands the answer is yellow, violet, red, then gold for ±5%. For 5 bands it is yellow, violet, black, brown, gold.
It may belong to E48, E96 or E192, which have values like 4.99 kΩ, 10.2 kΩ and 1.01 kΩ. Those parts are normally 5 band at ±2% or tighter. The page lists every E series that contains the value.
No. The values are processed in your browser and not uploaded, and they are not saved on your device. Reloading puts the 4.7 kΩ example back. The page only counts that a result was shown, without your values.