# Rounds per Minute Calculator (Rate of Fire) URL: https://speedycalculator.com/calculators/other/rounds-per-minute/ Last updated: 2026-10-30 > The rounds per minute calculator converts rounds fired and the time taken into a rate of fire in RPM and rounds per second, the time between shots and the time to empty a magazine, and estimates the sustained rate including reloads. ## Inputs - Number of rounds fired - Time taken to fire them (s, min, ms) - Magazine capacity (rounds) - Reload time (s, min, ms) ## Results - Rate of fire - Rounds per second - Time between shots - Time to empty one magazine - Sustained rate including reloads - Sustained rate as a share of the measured rate - Magazines used per minute of sustained fire ## Formula ``` RPM = rounds ÷ time (min) · rounds per second = RPM ÷ 60 · time between shots = 60 ÷ RPM (s) · sustained RPM = magazine ÷ (magazine ÷ rate + reload time) × 60 ``` ## Explanation Rate of fire describes how quickly a firearm, airsoft or paintball marker, or a weapon in a video game cycles rounds. The cyclic rate quoted by manufacturers is the mechanical maximum in continuous automatic fire – about 600 rounds per minute for an AK-47, 700–950 for an M4 carbine and around 3,900 for the GAU-8 cannon of the A-10 aircraft. That number is rarely what you get in practice. Magazines run empty within seconds, reloading takes time, barrels overheat and accuracy requires pauses, so the sustained or practical rate is far lower. Military manuals distinguish cyclic, rapid and sustained rates for exactly this reason. The calculator measures the rate from a count of rounds over a time (from a chronograph, a video or a game clip), converts it into every useful form and shows how much a given magazine size and reload time slow it down. It is equally handy for airsoft and paintball setups, game balancing and for checking the "fire rate" stats quoted in shooters. ### How to use the Rounds per Minute Calculator - **Number of rounds fired** - **Time taken to fire them** - **Magazine capacity (rounds)** - **Reload time** Results update as you type, every field has its own unit menu, and everything is calculated in your browser. ### How it works Divide the rounds by the time in minutes to get RPM, then convert. For the sustained rate the calculator adds the reload time to the time needed to fire one full magazine and divides the magazine size by that cycle. ### Worked example 30 rounds fired in 3 seconds: 30 ÷ 3 = 10 rounds per second = 600 RPM, one round every 100 ms. A 30-round magazine empties in 3 s; with a 2.5 s reload one cycle takes 5.5 s, so the sustained rate is 30 ÷ 5.5 × 60 = 327 RPM (54.5% of the measured rate). ### Typical cyclic rates WeaponCyclic rateM1911 / semi-automatic pistol (aimed)30–60 RPM practicalAK-47≈ 600 RPMM4 carbine700–970 RPMM249 light machine gun750–1,000 RPMGAU-8 Avenger (A-10)≈ 3,900 RPM ### Inputs explained FieldWhat to enterNumber of rounds firedA numberTime taken to fire themUnits: s, min, msMagazine capacity (rounds)A numberReload timeUnits: s, min, ms ### What each result means - **Rate of fire** = [Number of rounds fired]÷[Time taken to fire them]×60 - **Rounds per second** = [Number of rounds fired]÷[Time taken to fire them] - **Time between shots** = [Time taken to fire them]÷[Number of rounds fired]×1000 - **Time to empty one magazine** = [Magazine capacity (rounds)]÷([Number of rounds fired]÷[Time taken to fire them]) - **Sustained rate including reloads** = [Magazine capacity (rounds)]÷([Magazine capacity (rounds)]÷([Number of rounds fired]÷[Time taken to fire them]) + [Reload time])×60 - **Sustained rate as a share of the measured rate** = (([Magazine capacity (rounds)]÷([Magazine capacity (rounds)]÷([Number of rounds fired]÷[Time taken to fire them]) + [Reload time]))÷([Number of rounds fired]÷[Time taken to fire them]))×100 - **Magazines used per minute of sustained fire** = 60÷([Magazine capacity (rounds)]÷([Number of rounds fired]÷[Time taken to fire them]) + [Reload time]) ## Worked example Inputs — Number of rounds fired: 30; Time taken to fire them: 3 s; Magazine capacity (rounds): 30; Reload time: 2.5 s. Results — **Rate of fire = 600 RPM**; Rounds per second = 10 rounds/s; Time between shots = 100 ms; Time to empty one magazine = 3 s; Sustained rate including reloads = 327.3 RPM; Sustained rate as a share of the measured rate = 54.55 %; Magazines used per minute of sustained fire = 10.91. ## Key terms - **Cyclic rate**: Mechanical maximum rate of fire of an automatic weapon. - **Sustained rate**: Rate that can be kept up over time, including reloads and cooling. - **RPM**: Rounds per minute. - **Rounds per second**: RPM divided by 60. ## FAQ **How do I calculate rounds per minute?** Divide the rounds by the time in minutes: 30 rounds in 3 seconds (0.05 min) is 600 RPM. **What is the cyclic rate of fire?** The theoretical maximum of an automatic weapon firing continuously, ignoring reloading and heat. Real sustained rates are much lower. **How fast does an AK-47 fire?** Its cyclic rate is about 600 RPM – 10 rounds per second – so a 30-round magazine empties in about 3 seconds. **What is the fastest-firing gun?** Rotary cannons such as the GAU-8 Avenger (about 3,900 RPM) and the M134 Minigun (2,000–6,000 RPM) are among the fastest. **How much do reloads reduce the rate?** With a 30-round magazine at 600 RPM and a 2.5 s reload, the sustained rate drops to about 327 RPM – 55% of the cyclic rate. **How do I measure rate of fire from a video?** Count the shots between two frames and divide by the time between those frames; count the interval between the first and last shot carefully, because n shots span n − 1 intervals. ## Sources - [Wikipedia – Rate of fire](https://en.wikipedia.org/wiki/Rate_of_fire) - [Wikipedia – GAU-8 Avenger](https://en.wikipedia.org/wiki/GAU-8_Avenger) - [Wikipedia – AK-47](https://en.wikipedia.org/wiki/AK-47)