Resistor color code calculator

Resistor Color Code Calculator: decode any resistor in seconds from its color bands or SMD code, or go the other way and find the bands for any resistor value. A complete electronics bench tool for students, hobbyists, repair techs and engineers. This resistor calculator works fully offline, has no ads, and nothing you do leaves your phone. ★ RESISTOR COLOR CODE CALCULATOR - Read 3, 4, 5 and 6-band resistors - Tap a color and the resistor value, tolerance and real-world range update instantly - Two layouts: Classic, with the whole color grid on one screen, and Modern, with a large result card. Switch from the title bar; your choice is remembered - See the calculation written out (47×10² ±5%), the tolerance range, the E-series the value belongs to, and the temperature coefficient on 6-band parts - A realistic resistor drawing shows the bands exactly where they sit on the part - Copy or share any reading ★ REVERSE LOOKUP: RESISTOR VALUE TO COLOR BANDS - Type a resistance in ohms and a tolerance, get the band sequence that encodes it - Tells you whether it is an exact preferred value or the nearest one - Works for 3, 4, 5 and 6-band layouts - A quick ohm calculator for picking the right part from your drawer ★ SMD RESISTOR CODE CALCULATOR - 3-digit SMD codes (472 = 4.7 kΩ) - 4-digit EIA codes (4702 = 47 kΩ) - EIA-96 codes with the letter multiplier (01C = 10.0 kΩ, E-96, 1%) - R notation for decimals (4R7 = 4.7 Ω) - Underlined codes read in milliohms - A purpose-built keypad, so you are not fighting a phone keyboard ★ COLOR BAND CHART AND REFERENCE TABLES - The complete resistor color code chart: digit, multiplier and tolerance for all twelve colors - Preferred-value series at a glance - Always available, always offline ★ QUIZ: LEARN THE RESISTOR COLOR CODE - Six topics: band colors, reading a resistor, finding the bands, tolerance and range, SMD codes and preferred values - Six question types: multiple choice, true or false, type the answer, read the part, put in order and match the pairs - Four difficulties: Easy, Medium, Hard, and Adaptive, which follows how you are doing - An optional per-question timer - Every answer comes with an explanation of the rule behind it - Points, levels, day streaks, accuracy and eight badges to unlock - A daily challenge: five questions, the same for everyone that day - Spaced repetition: questions you get wrong come back at the right moment - Your best weeks, ranked - Sound effects you can switch off - Great for electronics students preparing for labs and exams ★ PRIVATE, OFFLINE AND AD-FREE - Works with no internet connection at all - No ads, anywhere - No account and no sign-in - No analytics, no tracking, no crash reporting - Nothing you calculate or answer ever leaves your device - Light and dark themes - Full screen-reader support, with every color named as well as shown A free resistor color code calculator with no ads and no in-app purchases.