Resistor Color Code Calculator

Decode a 4-band or 5-band resistor from its colour bands into resistance, tolerance and the min/max value range. Free, instant, no signup.

Formula: R = significant digits × multiplier (± tolerance)

How to use the Resistor Color Code Calculator

  1. Enter your values. Fill in the fields with your numbers.
  2. Calculate. Press Calculate to run the resistor color code calculator.
  3. Use the result. Copy the result or try a related tool next.

Why use our Resistor Color Code Calculator

Instant results. Enter your figures and the resistor color code calculator returns an answer in seconds.
Free & private. Runs in your browser — no signup, and nothing is sent to a server.
Accurate. Uses standard formulas so you can rely on the numbers.

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About the Resistor Color Code Calculator

The Resistor Color Code Calculator decodes the painted bands on a through-hole resistor into a resistance value in ohms, plus its tolerance and, on six-band parts, its temperature coefficient. Instead of memorising the standard color chart, you select the color of each band in order and the tool reads them the way a technician would: the colored stripes are a compact way to print specifications onto a component far too small for legible text. It handles the common 4-band format as well as 3-band, 5-band and 6-band resistors, returning the nominal value along with the minimum and maximum resistance the part is allowed to have.

Reach for this tool whenever you are stuck with a loose resistor and no datasheet, building a circuit from a kit, repairing a board, or checking that the part you grabbed from a drawer is the one your schematic calls for. The color system itself is standardised under IEC 60062, and the digit values are fixed: black 0, brown 1, red 2, orange 3, yellow 4, green 5, blue 6, violet 7, grey 8, white 9. Select the band count, click each color from left to right, and the calculator does the lookup and the maths for you, which is far quicker and less error-prone than counting stripes by eye.

The calculation follows the band positions exactly. On a 4-band resistor the first two bands are significant digits, the third is a power-of-ten multiplier, and the fourth is tolerance, so brown-black-red-gold becomes 10 x 100 = 1,000 ohms (1 kohm) at plus or minus 5%. A 5-band part adds a third significant digit before the multiplier for finer values like 4.7 kohm at 1% (yellow-violet-black-brown-brown), and a 6-band part appends a temperature-coefficient band. Gold and silver in the multiplier position mean x0.1 and x0.01, which is how sub-ohm values are coded.

Accuracy depends entirely on identifying the colors correctly, and that is the one genuinely tricky part: red and orange, or blue and green, can look alike under poor lighting or on aged, heat-darkened components. The tolerance band tells you how far the real part may legally drift from its nominal value, so the calculator also shows that range; for anything critical, confirm with a multimeter. This calculator runs entirely in your browser. The band colors you pick are processed on your own device to produce the result and are never uploaded, logged, or tied to an account.

Frequently asked questions

How do I know which end of the resistor to start reading from?

Read so the tolerance band ends up on the right. A gold or silver band is always the tolerance band and is never a digit, so put it on the right and read the others left to right. If there is no metallic band, the wider gap usually sits before the last band, or start from the band closest to a lead.

What is the difference between a 4-band and a 5-band resistor?

A 4-band resistor uses two significant digits, a multiplier, and a tolerance band. A 5-band resistor adds a third significant digit before the multiplier, allowing more precise values, which is why 1% and tighter resistors are usually 5-band.

What do gold and silver bands mean?

It depends on position. As the tolerance band, gold means plus or minus 5% and silver means plus or minus 10%. As the multiplier band, gold means multiply by 0.1 and silver means multiply by 0.01, which is how resistors below 10 ohms are coded.

What does the tolerance band actually tell me?

It states how far the resistor's true resistance may differ from its printed value. A 1 kohm resistor at 5% tolerance can measure anywhere from 950 to 1,050 ohms and still be in spec, so the calculator shows that minimum-to-maximum range.

Why don't my measured ohms exactly match the calculated value?

A resistor is only guaranteed to fall within its tolerance band, so small differences are normal and expected. Larger gaps usually mean a misread color, often red versus orange or blue versus green, so double-check the bands or confirm with a multimeter.

From our blog

Daily Fat Grams Made Simple: How to Set and Hit Your Target

By the Super Simple Digital Tools Team · Updated June 2026

Fat has spent decades swinging between villain and hero in diet headlines, and that whiplash is exactly why a calculator helps. Instead of arguing about whether fat is good or bad, you can anchor your plan to a clear number. The starting point is always your total daily calories, because fat is expressed as a slice of that total. Once you know roughly how many calories you eat to maintain, lose, or gain weight, the fat question stops being philosophical and becomes arithmetic you can actually act on at the grocery store and the dinner table.

Choosing your percentage is the one judgment call the calculator cannot make for you. A reasonable default for most people is 25 to 30 percent of calories from fat, which lands comfortably inside the 20 to 35 percent window that public-health bodies recommend. If you prefer a higher-carb, lower-fat style of eating, drift toward 20 percent. If you eat low-carb, you will naturally rise toward the top of the range or beyond. The percentage you pick should reflect a way of eating you can sustain, not a number that looks impressive for a week and collapses afterward.

After you have a percentage, the conversion is quick: calories times percentage, divided by nine. Suppose you eat 1,800 calories and target 28 percent fat. That is 1,800 x 0.28 = 504 fat calories, and 504 divided by 9 is 56 grams per day. Keep that figure visible while you log meals, because fat hides in places labels make easy to overlook, including dressings, sauces, cooking oil, baked goods, and cheese. A single tablespoon of oil is around 14 grams, so a couple of generous pours can quietly use up a quarter of your daily allowance.

The number on the calculator tells you how much, but it says nothing about what kind, and the kind is where most of the health payoff lives. Prioritize unsaturated fats from olive oil, avocados, nuts, seeds, and oily fish, which support heart and brain health and supply the essential omega-3 fatty acids your body cannot make on its own. Treat saturated fat as a sub-budget inside your total, ideally under 10 percent of calories, and avoid artificial trans fats entirely. Two diets can hit the same fat-gram target and still differ enormously in their effect on cholesterol and long-term risk.

Finally, use the calculator as a recurring tool rather than a one-time lookup. Recalculate whenever your calorie needs change, such as after losing weight, ramping up training, or shifting your eating style. Run a few what-if scenarios side by side to see how moving from 20 to 35 percent reshapes your daily grams, then sanity-check the result against how full and energetic you feel. The goal is a target that is specific enough to guide real choices yet flexible enough to live with for months, not a rigid figure you dread.

  • Lock in an accurate daily calorie figure first; if your calorie estimate is off, the fat-gram target inherited from it will be off too.
  • Remember each gram of fat is 9 calories, so small extras add up fast. One tablespoon of oil is about 14 grams of fat.
  • Set a separate ceiling for saturated fat, roughly under 22 grams on a 2,000-calorie diet, and fill the rest with unsaturated sources.
  • Do not chase ever-lower fat. Stay at or above 20 percent of calories so you still get essential fatty acids and fat-soluble vitamins.

Read the full guide →

Tool by the Super Simple Digital Tools Team. Reviewed by our editorial team. Free to use, no signup required.

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