Which end do you read a resistor color code from?

Hold the resistor with the gold or silver (tolerance) band on the right and read from the left band. The tolerance band is often slightly separated from the others. The first band is almost never black, so if it starts with black you may be reading it backwards. This tool warns you when, for example, the reverse reading gives an E-series value.

What is the color code for 4.7 kΩ?

On a 4-band resistor it is yellow, violet, red plus a tolerance band (gold for ±5%). Yellow 4 and violet 7 make 47, and red is × 100, so 47 × 100 = 4,700 Ω. On a 5-band resistor it is yellow, violet, black, brown (470 × 10) plus a tolerance band (brown for ±1%).

What are the color codes for 10 kΩ, 1 kΩ and 220 Ω?

On 4-band resistors, 10 kΩ is brown, black, orange; 1 kΩ is brown, black, red; and 220 Ω is red, red, brown, each followed by a tolerance band. A 5-band 10 kΩ resistor is brown, black, black, red plus a tolerance band.

How do you read SMD resistor codes like 103 or 4R7?

In a 3-digit code the first two digits are the value and the third is the number of zeros: 103 is 10 × 10³ = 10 kΩ and 472 is 4.7 kΩ. In a 4-digit code the first three digits are the value, so 1002 is 100 × 10² = 10 kΩ. R marks the decimal point, so 4R7 is 4.7 Ω. Two digits and a letter such as 01C is EIA-96: 01 is 100 in the E96 series and C is × 100, so it is 10 kΩ.

How do you calculate the resistor for an LED?

It is (supply voltage − LED forward voltage) ÷ current. For a red LED (about 2.0 V) at 10 mA from 5 V, (5 − 2.0) ÷ 0.01 = 300 Ω, so pick the next E12 value up, 330 Ω. The current is then about 9.1 mA and the resistor dissipates about 27 mW, so a 1/8 W or larger resistor is enough.

What are the E12 and E24 series?

They are the standard sequences of resistor values. E12 divides each decade into 12 steps: 10, 12, 15, 18, 22, 27, 33, 39, 47, 56, 68 and 82. E24 fills in between for 24 steps. E6 is used for ±20%, E12 for ±10%, E24 for ±5%, E48 for ±2% and E96 for ±1% resistors. If the value you need isn't available, you can make it with two resistors in series or parallel (5 kΩ is two 10 kΩ resistors in parallel).

Resistor Color Code Calculator | Colors to Ohms and Ohms to Colors (4, 5 and 6 Bands), Which End to Read From, E12, E24 and E96 Value Charts, SMD Resistor 3-Digit, 4-Digit and EIA-96 Codes, LED Resistor Calculator, Series and Parallel Resistance

The Resistor Color Code Calculator is a free tool for electronics hobbyists asking “how many ohms is this resistor?” or “what colors is 4.7 kΩ?”. Tap the band colors from left to right while looking at the resistor drawing to see the resistance, tolerance, actual range of values and temperature coefficient. It supports 4-band (two digits + multiplier + tolerance), 5-band (three digits), 6-band (with temperature coefficient) and 3-band resistors, and when the reading looks backwards, such as starting with black or giving a value outside the E series, it shows the reverse reading. In the value-to-colors tab, enter a value such as 4.7k, 4k7 or 2R2 to get the band colors and a drawing, the nearest values above and below in the E12, E24 and E96 series, and the SMD resistor code. There is also a decoder for SMD resistor markings (3-digit such as 103, 4-digit such as 1002, R notation such as 4R7 and EIA-96 such as 01C), an LED current-limiting resistor calculator ((supply voltage − Vf) ÷ current) with wattage selection, series and parallel resistance, and a search for one or two E-series resistors that make a target value. A color code table and a chart of values and color codes for each E series are included.

Read the resistance from the band colors

Choose the number of bands and tap the colors starting from the left band. The side with the gold or silver band is the right (last) end.

Band 1 (digit)

Band 2 (digit)

Band 3 (multiplier)

Band 4 (tolerance)

4.7kΩ ±5%

47 × 10^2 = 4700Ω

Actual range: 4.465kΩ to 4.935kΩ

This is an E6 series value

ABOUT

About Resistor Color Code Calculator | Colors to Ohms and Ohms to Colors (4, 5 and 6 Bands), Which End to Read From, E12, E24 and E96 Value Charts, SMD Resistor 3-Digit, 4-Digit and EIA-96 Codes, LED Resistor Calculator, Series and Parallel Resistance

The Resistor Color Code Calculator is a free tool that reads the resistance and tolerance from a resistor's band colors and looks up the color code for a resistance value. It supports 4, 5 and 6 bands, checks whether you are reading it backwards, and includes E-series charts, an SMD resistor code decoder, an LED current-limiting resistor calculator and series/parallel resistance.

How to use Resistor Color Code Calculator | Colors to Ohms and Ohms to Colors (4, 5 and 6 Bands), Which End to Read From, E12, E24 and E96 Value Charts, SMD Resistor 3-Digit, 4-Digit and EIA-96 Codes, LED Resistor Calculator, Series and Parallel Resistance

1In “Colors to ohms”, choose the number of bands (4, 5, 6 or 3)
2Hold the resistor with the gold or silver band on the right and tap the colors from the left band
3Check the resistance, tolerance and actual range. If it looks backwards a warning appears, so use “Swap left and right” to check
4To find the colors for a value, enter something like 4.7k or 10k in “Ohms to colors”
5Use the other tabs for SMD resistor markings, LED resistors and combined resistance

Great for

Find out how many ohms a resistor in a kit or parts box is from its band colors
Find the 4.7 kΩ or 10 kΩ resistor from a schematic by its color code
Check which way round to read a resistor when you aren't sure
Read SMD resistor markings such as 103, 4R7 or 01C on a circuit board
Choose the resistance and wattage for lighting an LED from an Arduino or Raspberry Pi
Combine resistors you have in series or parallel to make the value you need

Good to know

A 4-band resistor is digit, digit, multiplier, tolerance; a 5-band resistor is digit, digit, digit, multiplier, tolerance; a 6-band resistor adds a temperature coefficient band at the end. A 3-band resistor has no tolerance band and is ±20%.
The digits are black 0, brown 1, red 2, orange 3, yellow 4, green 5, blue 6, violet 7, grey 8 and white 9. As a multiplier, gold is × 0.1 and silver is × 0.01.
Tolerances are brown ±1%, red ±2%, green ±0.5%, blue ±0.25%, violet ±0.1%, gold ±5% and silver ±10%. Grey is ±0.01% as in IEC 60062:2016 (older tables say ±0.05%).
The LED resistor is (supply voltage − LED forward voltage × number of LEDs) ÷ current, and the tool picks the next E-series value above the result so the current doesn't exceed your target. The resistor wattage should be at least twice the power it dissipates.
LED forward voltages are typical values for each color. Check the LED's datasheet for the actual value.
Colors on screen can differ from real ones. If you can't tell brown from red or grey from white, measure the resistor with a multimeter.

Questions this tool answers

Use Resistor Color Code Calculator | Colors to Ohms and Ohms to Colors (4, 5 and 6 Bands), Which End to Read From, E12, E24 and E96 Value Charts, SMD Resistor 3-Digit, 4-Digit and EIA-96 Codes, LED Resistor Calculator, Series and Parallel Resistance for searches like these:

Learn how to read resistor color codes
Calculate a resistance from band colors
Look up the color code for a resistance value
Find out which end of a resistor to read from
Learn how to read SMD resistor codes
Calculate the resistor for an LED

FAQ

Which end do you read a resistor color code from?: Hold the resistor with the gold or silver (tolerance) band on the right and read from the left band. The tolerance band is often slightly separated from the others. The first band is almost never black, so if it starts with black you may be reading it backwards. This tool warns you when, for example, the reverse reading gives an E-series value.
What is the color code for 4.7 kΩ?: On a 4-band resistor it is yellow, violet, red plus a tolerance band (gold for ±5%). Yellow 4 and violet 7 make 47, and red is × 100, so 47 × 100 = 4,700 Ω. On a 5-band resistor it is yellow, violet, black, brown (470 × 10) plus a tolerance band (brown for ±1%).
What are the color codes for 10 kΩ, 1 kΩ and 220 Ω?: On 4-band resistors, 10 kΩ is brown, black, orange; 1 kΩ is brown, black, red; and 220 Ω is red, red, brown, each followed by a tolerance band. A 5-band 10 kΩ resistor is brown, black, black, red plus a tolerance band.
How do you read SMD resistor codes like 103 or 4R7?: In a 3-digit code the first two digits are the value and the third is the number of zeros: 103 is 10 × 10³ = 10 kΩ and 472 is 4.7 kΩ. In a 4-digit code the first three digits are the value, so 1002 is 100 × 10² = 10 kΩ. R marks the decimal point, so 4R7 is 4.7 Ω. Two digits and a letter such as 01C is EIA-96: 01 is 100 in the E96 series and C is × 100, so it is 10 kΩ.
How do you calculate the resistor for an LED?: It is (supply voltage − LED forward voltage) ÷ current. For a red LED (about 2.0 V) at 10 mA from 5 V, (5 − 2.0) ÷ 0.01 = 300 Ω, so pick the next E12 value up, 330 Ω. The current is then about 9.1 mA and the resistor dissipates about 27 mW, so a 1/8 W or larger resistor is enough.
What are the E12 and E24 series?: They are the standard sequences of resistor values. E12 divides each decade into 12 steps: 10, 12, 15, 18, 22, 27, 33, 39, 47, 56, 68 and 82. E24 fills in between for 24 steps. E6 is used for ±20%, E12 for ±10%, E24 for ±5%, E48 for ±2% and E96 for ±1% resistors. If the value you need isn't available, you can make it with two resistors in series or parallel (5 kΩ is two 10 kΩ resistors in parallel).

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