2.7 kΩ resistor color code
A 2.7 kΩ resistor is Red, Violet, Red, Gold: 27 × 100 = 2,700 Ω, ±5%, so anything from 2.565 to 2.835 kΩ is in spec.
27 × 100 = 2,700 Ω = 2.7 kΩ
5-band version
Red · Violet · Black · Brown · Brown = 2.7 kΩ ±1%
270 × 10 = 2,700 Ω = 2.7 kΩ. Range 2.673–2.727 kΩ (±1%).
Open the 5-band version
Where you'll meet it
A battery-saving power light on 9 V
Gadgets that run for hours from a 9 V battery, such as a guitar effect pedal, light their power LED with only a few milliamps, so the light barely drains the battery. Here a 2.7 kΩ resistor sits between the battery's plus and a red LED.
I = (9 V − 2.0 V) / 2.7 kΩ ≈ 2.6 mA
That is far under the 20 mA a standard LED is rated for. A modern high-efficiency LED is plainly lit at that current; an old diffused one looks dim.
A blue or white LED drops about 3.0 V, so the same resistor gives (9 V − 3.0 V) / 2.7 kΩ ≈ 2.2 mA.
The resistor turns (2.6 mA)² × 2.7 kΩ ≈ 0.018 W into heat, so any ¼ W (0.25 W) part is fine.
2.0 V and 20 mA are typical figures for a standard 5 mm red LED. Check your LED's datasheet. A fresh battery reads a little over 9 V and sags as it empties, so the current drifts with it. The LED's longer leg goes toward the battery's plus. If it stays dark, turn it round: 9 V backwards is more than the 5 V most LEDs are rated to block.
On SMD parts
Look for 272 or 2701
- 272272 = 27 × 10² = 2,700 Ω (3-digit code).
- 27012701 = 270 × 10¹ = 2,700 Ω (4-digit code, usually ±1% parts).
There is no EIA-96 code, because 2.7 kΩ is not an E96 value (the nearest E96 values are 2.67 kΩ and 2.74 kΩ).
Don't mix it up
Only band 3 changes
These four share Red, Violet and Gold. Red (×100) is 2.7 kΩ; brown is ten times less and orange ten times more.
270 Ωband 3 brown- 2.7 kΩband 3 redThis page
27 kΩband 3 orange
270 kΩband 3 yellow
Check it with a meter
Read 2.565–2.835 kΩ
- Take the resistor out of the circuit.
- Set the meter to Ω, range 20 kΩ (or auto).
- Touch one probe to each lead. Keep your fingers off the metal: your body is a resistor too.
- Anything from 2.565 to 2.835 kΩ is a good ±5% part. A 5-band ±1% part should read 2.673 to 2.727 kΩ.
A meter has a small error of its own, so a reading a hair outside the range does not prove the part is bad. Measure again with firm contact before you swap it.
Spot it
Can you find 2.7 kΩ in a pile?
Practise reading it, and its look-alikes, in the resistor challenge.
Try the resistor challenge2.7 kΩ resistor FAQ
Why does a 9 V project use 2.7 kΩ for its power LED?
To save the battery. With a typical red LED (about 2.0 V), 2.7 kΩ sets (9 V − 2.0 V) / 2.7 kΩ ≈ 2.6 mA: enough to show that the device is on, and far less than the 20 mA a standard LED can take. A smaller resistor makes the LED brighter and drains the battery faster.
What is the SMD code for a 2.7 kΩ resistor?
272 on 3-digit parts (27 × 10²) and 2701 on 4-digit parts (270 × 10¹). There is no EIA-96 code, because 2.7 kΩ is not an E96 value.
What are the 5-band colors for 2.7 kΩ?
Red, Violet, Black, Brown, Brown: 270 × 10 = 2.7 kΩ with ±1% tolerance, so 2.673 to 2.727 kΩ.
What does 2k7 mean?
2k7 is another way to write 2.7 kΩ. The k sits where the decimal point would be, so the point cannot get lost in small print or on a schematic. You will also see it written as 2.7k or 2K7.
Bands, ranges and codes come from the same engine as the calculator. Last reviewed .