What next?
Frame time is the honest version of FPS. These are the settings that move it.
What your result means
Frame time is how long one frame is on your screen. It is the same information as the frame rate, stated in the unit that actually matters for feel: at 60 fps every frame holds for 16.7 ms, and at 240 fps for 4.2 ms. Refresh interval is the same figure for your monitor — how often the panel can show something new. Frames per refresh compares them: below 1 the panel repeats frames, above 1 the game is producing frames the panel cannot all display. Saved per frame is the part worth reading before spending money, because frame rate improvements convert to milliseconds on a curve that flattens hard.
Why this one is different
The optional second frame-rate box is the point of this one: name the rate you are weighing up and the answer arrives as milliseconds saved per frame, which is the honest size of an upgrade rather than a bigger count of frames. A closing line says whether your panel can display those extra frames at all — above its refresh rate they are rendered and never shown.
60 to 120 fps saves 8.3 ms. 240 to 300 saves 0.8 ms.
Frame rate is a rate and frame time is its reciprocal, so equal-sized jumps in frames buy wildly unequal amounts of time. Going from 60 to 120 fps removes 8.33 ms per frame. Going from 120 to 180 removes 2.78 ms. From 240 to 300, 0.83 ms — a tenth of the first upgrade, for the same 60 extra frames.
This is not an argument against high frame rates; there are real reasons to want them, and lower frame time is genuinely lower latency. It is an argument for knowing the size of what you are buying. Put both numbers in above and read the millisecond figure rather than the frame count, because the frame count systematically overstates the difference at the top end.
How it works
Frame time is one divided by frame rate. Working in milliseconds makes it 1000 ÷ fps, so 144 fps is 1000 ÷ 144 = 6.944 ms. Your monitor’s refresh interval is the same operation on its refresh rate: 240 Hz is 1000 ÷ 240 = 4.167 ms. Dividing the frame rate by the refresh rate gives frames per refresh, which is what determines whether the panel is waiting for the game or the game is producing frames the panel will never show. The comparison figure is simply the difference between two frame times.
How to use this calculator
- Enter the frame rate you actually get. Use an average from your overlay rather than a peak, and if you care about smoothness use the 1% low instead — that is the frame time you feel.
- Enter your monitor refresh rate in Hz. Check it is set to the panel’s maximum in your display settings; monitors frequently ship at 60 Hz.
- Optionally enter a frame rate to compare against — the one an upgrade or a settings change would give you.
- Read the milliseconds saved, not the frames gained. That is the number that describes what changes.
Formula
fps = frames rendered per second, Hz = refreshes the display performs per second, 1000 = milliseconds in a second. Frames per refresh is fps ÷ Hz, and the gain from an upgrade is the difference of two frame times: 1000 ÷ old − 1000 ÷ new.
Example calculation
A player at 144 fps on a 240 Hz monitor, wondering what hitting 240 fps would be worth:
Refresh interval = 1000 ÷ 240 = 4.167 ms
Frames per refresh = 144 ÷ 240 = 0.60 : 1
At 240 fps, frame time = 1000 ÷ 240 = 4.167 ms
Saving = 6.944 − 4.167 = 2.778 ms per frame
2.8 ms is a real improvement and a small one — roughly the time it takes sound to travel a metre. Whether it is worth a graphics card is a judgement, but it should be made against 2.8 ms rather than against "96 more frames".
Frequently asked questions
Is frame time better than frame rate?＋
It is the same information stated more usefully. Frame rate averages over a second, which hides the thing you notice: a single 40 ms frame inside an otherwise smooth second barely moves the average but is plainly visible as a stutter. Frame time is per frame, so tools that graph it show you the spikes an average conceals. Use frame rate to describe performance, frame time to diagnose it.
Should my frame rate match my refresh rate?＋
With variable refresh rate — G-SYNC or FreeSync — the panel follows the game, so anything inside its range is smooth and there is nothing to match. Without it, exceeding the refresh rate causes tearing and sitting below it causes uneven frame pacing. The common recommendation with VRR is to cap a few frames below the maximum so the display stays inside its variable range.
Does more fps than my Hz do anything at all?＋
For smoothness, very little — the panel can only show what it can show. For latency, yes: a frame that finishes rendering sooner is a frame that can be scanned out sooner, so extra frames shave a small amount off the delay between your input and the picture. This tool quantifies the frame-time part of that; it does not model the whole input chain, which includes polling, queueing and the display’s own processing.
What is a 1% low and why does it matter more?＋
It is the average of the worst one per cent of frames — in effect the frame time of your bad moments. A game averaging 144 fps with a 1% low of 45 fps feels worse than a steady 100 fps, because the 22 ms spikes are what you perceive. If you are choosing settings for feel rather than for a benchmark number, put your 1% low into this tool instead of your average.
Why does 30 fps feel so much worse than 60 when the gap is only 30 frames?＋
Because the frame-time gap is enormous: 33.3 ms against 16.7 ms, a 16.6 ms difference. The same 30-frame gap from 120 to 150 fps is 1.7 ms. Frames are a rate and time is its reciprocal, so frame differences at the bottom of the scale are worth ten times more than identical frame differences at the top.
Does this account for input lag from my monitor?＋
No, and no calculator can from a frame rate alone. Panel processing, pixel response, scan-out time and the input chain in front of the game all add latency that has nothing to do with how fast frames are produced. Frame time is one component of end-to-end latency, usually a large one, but treating it as the whole figure will understate what you actually feel.
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Assumptions & limitations
Every figure here comes from a simplified model. Keep these limits in mind when reading your result:
- Frame time is derived from the frame rate you enter and nothing else. Real frame times vary continuously; an average frame rate produces an average frame time and hides the variance that you actually perceive.
- Does not model end-to-end input latency. Input polling, render queue depth, display processing and pixel response are all outside a frame-rate figure.
- Assumes a fixed refresh rate for the frames-per-refresh comparison. With G-SYNC or FreeSync active inside its range the panel tracks the game, so the ratio describes the fixed-refresh case only.
- Assumes your monitor is actually running at the refresh rate you enter. A panel left at its default 60 Hz is one of the most common causes of a mismatch here.
- Frame generation and interpolation break the relationship between rendered frames and latency: the displayed frame rate rises while the latency of a genuine input response does not fall with it.