Frame Rate to Milliseconds Calculator: FPS to Frame Time and Back
Convert FPS to frame time in milliseconds and microseconds, frame time back to FPS, or a frame count to a duration, with exact NTSC rates (23.976, 29.97, 59.94) and a table of frame budgets from 24 to 480 FPS.
How it works
Frame time (ms) = 1,000 ÷ FPS · Frame time (µs) = 1,000,000 ÷ FPS · FPS = 1,000 ÷ frame time (ms) · Duration (ms) = frames ÷ FPS × 1,000 · NTSC rates: 23.976 = 24000/1001, 29.97 = 30000/1001, 59.94 = 60000/1001
Frame rate and frame time are reciprocals: one second holds 1,000 milliseconds, so at 60 FPS each frame gets 1,000 ÷ 60 = 16.667 ms. That frame budget is the deadline a game engine or video pipeline must meet; if the work for one frame takes longer, the frame rate drops. Developers and benchmark tools talk in frame times because milliseconds add up: a 3 ms shader pass and a 5 ms physics step take 8 ms of a 16.7 ms budget, while “FPS lost” figures do not add. Switch to ms → FPS to turn a frame-time reading back into a frame rate, or to Frames → time to find how long a number of frames lasts, which is how video editors and subtitle tools convert frame counts to timestamps. Broadcast video in the Americas and Japan runs at 1000/1001 of the round rate (24000/1001 = 23.976, 30000/1001 = 29.97, 60000/1001 = 59.94 FPS); with the NTSC option on, the calculator uses those exact values, so 120 frames at 29.97 FPS last exactly 4,004 ms. The same maths applies to monitor refresh rates: a 144 Hz panel refreshes every 6.944 ms. End-to-end input lag is longer than one frame time because it also includes input polling, the render queue and display scan-out.
Worked example
At 60 FPS the budget is 1,000 ÷ 60 = 16.667 ms per frame, or 16,666.7 µs, and 3,600 frames are drawn each minute. Drop to 30 FPS and each frame gets 33.333 ms; at 144 FPS the budget shrinks to 6.944 ms. In Frames → time mode, 120 frames at 29.97 FPS (30000/1001) last 120 × 1,001 ÷ 30,000 s = 4,004.0 ms, the subtitle timestamp 00:00:04,004.
Sources: West Games: Refresh rate to frame time calculator (60 Hz = 16.67 ms, 144 Hz = 6.94 ms, 240 Hz = 4.17 ms) · Calculator Academy: Frames to ms calculator (120 frames at 30000/1001 fps = 4,004 ms) · Wikipedia: Frame rate (60/1.001 ≈ 59.94 fields per second)
Frequently asked questions
Why is 60 FPS about 16.7 ms?
One second holds 1,000 milliseconds, and 60 frames share it evenly: 1,000 ÷ 60 = 16.667 ms per frame. That is the classic “16 ms budget” game developers optimise against; 30 FPS gives 33.3 ms.
What frame time do I need for 120, 144 or 240 Hz?
1,000 ÷ 120 = 8.33 ms, 1,000 ÷ 144 = 6.94 ms and 1,000 ÷ 240 = 4.17 ms. Higher refresh rates leave far less time per frame, so the CPU and GPU work per frame has to be leaner to keep up.
How do I convert milliseconds to FPS?
Divide 1,000 by the frame time. A 10 ms frame time is 100 FPS and 25 ms is 40 FPS. Average the frame times first and then convert; averaging FPS values from uneven frames overstates the frame rate.
How long is one frame at 23.976 or 29.97 FPS?
23.976 FPS is exactly 24000/1001, so one frame lasts 1001/24 = 41.708 ms. 29.97 FPS is 30000/1001, so a frame lasts 33.367 ms, slightly longer than the 33.333 ms of true 30 FPS.
Is frame time the same as input lag?
No. Frame time is how often a new frame is produced. The delay you feel also includes input polling, the render queue and display scan-out, so end-to-end latency is usually two to several frame times.
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This calculator is for educational purposes. Double-check important results before acting on them.