1/4 Watt

1/4 watt metal film resistors with 1% tolerance — the standard resistor for LED circuits.

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1/4 watt metal film resistors with 1% tolerance — the standard resistor for LED circuits. The 1/4W (250mW) power rating handles any single-LED circuit running at 5V, 9V, or 12V, which covers the vast majority of hobby, automotive, and model railroad projects you will ever build. Metal film construction delivers tight 1% tolerance for consistent LED brightness across every LED in your build — no dim outliers, no hot spots, no visible variation from one LED to the next.

We stock the full E24 standard value series, giving you the exact resistance you need for any LED and supply voltage combination. No rounding to the nearest available value, no compromising on brightness or current. Whether you need 47Ω for a 3.3V Arduino GPIO pin driving a status LED, 150Ω for a 5V breadboard indicator, 220Ω for a 5V panel-mount LED, 330Ω for a 9V battery-powered circuit, 470Ω for a 12V blue or white LED, 510Ω for a 12V red or yellow LED, or 1KΩ for dimming a model railroad structure light to a warm subdued glow — the precise value is here. Every value is available in convenient quantities for single projects and bulk packs for large builds like full layout lighting or commercial sign assembly.

When to use 1/4 watt: Use 1/4W resistors whenever the power dissipation stays below 250mW. The quick check: multiply the voltage dropped across the resistor by the current flowing through it. A 470Ω resistor limiting a 3.2V blue LED on a 12V supply drops 8.8V at ~19mA = 0.167W — well within the 1/4W rating with room to spare. A 510Ω resistor limiting a 2.0V red LED on 12V drops 10V at ~20mA = 0.196W — also safe. In fact, a 1/4W resistor handles any single standard 20mA LED on supply voltages up to about 18V. If your calculation exceeds 250mW — which happens with multiple LEDs on one resistor, supply voltages above 18V, or high-current LEDs — step up to a 1/2 watt resistor. For circuits exceeding 500mW, use a 1 watt resistor.

Physical size and form factor: A standard 1/4W axial metal film resistor measures approximately 6.3mm long by 2.3mm in diameter (body only, not including wire leads). The leads are spaced to fit standard 2.54mm (0.1 inch) pitch breadboards, perfboards, and through-hole PCB footprints. This is the most common resistor form factor in hobby electronics — the size you see in every Arduino tutorial, every electronics kit, and every beginner's breadboard project. They fit comfortably inside project enclosures, behind instrument cluster faceplates, inside guitar pedal housings, and in the tight spaces of model railroad buildings. If you need an even smaller footprint for PCB-based projects, our 1/8W 0805 SMD resistors are the surface-mount alternative.

Common applications for 1/4W resistors: LED current limiting is by far the most common use — a single resistor paired with a single LED on a DC power supply. But 1/4W resistors also serve as pull-up and pull-down resistors (typically 4.7KΩ or 10KΩ) on Arduino and ESP32 GPIO pins, voltage divider resistors for level-shifting between 5V and 3.3V logic, timing resistors in 555 timer circuits for LED flashers and PWM dimmers, signal path resistors in guitar pedal circuits (gain stages, tone stacks, output buffers), bias resistors for transistor switching circuits that drive LED arrays, and current sense resistors in battery-monitoring circuits. The 1/4W rating is sufficient for all of these low-power applications.

Specific use cases where 1/4W resistors are the standard: automotive instrument cluster LED swaps (GM, Ford, Toyota, Honda gauge backlighting where each bulb socket gets one LED plus one resistor), model railroad layout lighting (building interiors, platform lights, crossing signal circuits, block signal indicators — often dozens of LEDs each with their own resistor), guitar pedal builds (signal path and indicator LED resistors on builds from PedalPCB, Aion Electronics, BYOC, and DIY layouts), arcade button illumination (per-button LED current limiting), escape room and Halloween props (LED eyes, indicator panels, effect lighting), and holiday display wiring (individual LED ornaments and decorations powered by battery packs).

Not sure which value you need? Use our LED Resistor Calculator — enter your supply voltage and LED specs, and it returns the exact resistor value from our inventory. Need to identify a resistor by its color bands? See our Resistor Color Code Chart. For complete wiring instructions, read our How to Wire LEDs — 101 guide. Pair these resistors with our component LEDs (700+ varieties in every size and color), or skip the resistor entirely with pre-wired LEDs that come with the resistor already attached.

Frequently Asked Questions

Yes, for the vast majority of single-LED circuits. A standard 20mA LED on a 12V supply through a 470Ω resistor dissipates about 0.17W — well within the 1/4W (0.25W) limit. You only need a higher wattage when running multiple LEDs through a single resistor, using supply voltages above 18V, or driving high-current LEDs at 50mA or more. For those cases, step up to a 1/2 watt resistor.
For a red, orange, or yellow LED (2.0V forward voltage) at 20mA on 12V: use a 510Ω 1/4W resistor. For a blue, green, white, or UV LED (3.0–3.2V forward voltage): use a 470Ω 1/4W resistor. These are the two most popular values we sell. For exact values at other supply voltages (5V, 9V, 24V), use our LED Resistor Calculator.
Metal film resistors use a thin layer of metal deposited on a ceramic core, then laser-trimmed to a precise resistance value. They offer tighter tolerance (1% vs. 5% for carbon film), lower electrical noise, and better temperature stability. For LED circuits, the 1% tolerance means every LED in your project receives the same current and glows at the same brightness — critical for automotive instrument cluster LED swaps, model railroad building arrays, and any project where matched brightness matters.
A standard 1/4W axial metal film resistor measures approximately 6.3mm long by 2.3mm in diameter (body only, not including leads). The wire leads are spaced to fit standard 2.54mm (0.1 inch) pitch breadboards, perfboards, and through-hole PCB footprints. This is the most common through-hole resistor size in hobby electronics. For comparison, a 1/2W resistor is about 9mm x 3.2mm, and a 1W resistor is about 11mm x 4.5mm.
It depends on the power dissipation. A 1KΩ resistor on 24V with a 2V red LED drops 22V at 22mA = 0.484W — that exceeds the 1/4W (0.25W) rating and the resistor would overheat. You need a 1/2 watt resistor or a 1 watt resistor for 24V single-LED circuits. Always calculate power dissipation (P = Vdrop × I) before choosing your resistor wattage.
Metal film 1% resistors have five color bands. The first three bands represent the significant digits, the fourth band is the multiplier, and the fifth band indicates tolerance (brown = 1%). For example, a 470Ω resistor reads: yellow (4), violet (7), black (0), black (×1), brown (1%). See our Resistor Color Code Chart for the complete color-to-value table and visual guide.