Why is headroom negative?

It means your workload takes longer than the frame budget. Lower the workload or frame rate to prevent drops.

Does this account for GPU/CPU split?

It treats your workload as a combined number. Profile CPU and GPU separately if you need deeper insight.

How much headroom should I leave?

Aim for at least 10–20% free to handle spikes, IO, and OS overhead without hitching.

Can I use this for VR/AR frame targets?

Yes. Enter your target (e.g., 72/90/120). VR benefits from more headroom to avoid discomfort.

Does vsync/VRR change the math?

Frame pacing still matters—work must fit within the frame time even with adaptive sync.

tech calculator

Frame Time Calculator

Convert FPS into milliseconds per frame and see how much budget your render/update loop is using.

Results

Frame time (ms): 16.67
Frame time (µs): 16666.67
Headroom remaining (ms): 6.67
Budget used: 60.00%

How to use this calculator

Enter your target frame rate (FPS).
Enter workload per frame in milliseconds.
See frame time, headroom, and percent of budget used.

Inputs explained

Frame rate (FPS): Refresh target you’re aiming to hit (e.g., 60, 90, 120, 144).
Workload per frame (ms): Total time your game/app spends each frame (logic + render).

How it works

Frame time = 1000 ÷ FPS. We compare that budget to the time you spend per frame to see headroom and percent usage.

If headroom is negative, the workload is heavier than the target FPS allows, so frames will drop or jitter.

Formula

Frame time (ms) = 1000 ÷ FPS
Headroom = Frame time − Workload

When to use it

Profiling game loops to verify if you can sustain 60/120/144 FPS.
Budgeting animation or visualization pipelines for smooth playback.
Planning CPU/GPU headroom for realtime dashboards or XR workloads.

Tips & cautions

Target 10–20% headroom to absorb spikes and OS tasks.
If headroom is negative, cut work or lower FPS until the budget fits.
Combine with a profiler to split CPU vs GPU time and tackle the bottleneck.
Single combined workload input—does not separate CPU/GPU or threads.
Assumes fixed FPS targets; adaptive sync scenarios may behave differently.
No frame pacing or jitter analysis—use profiling tools for detailed timing.

Worked examples

60 FPS target, 10 ms workload

Frame time ≈ 16.67 ms
Headroom ≈ 6.67 ms
Budget used ≈ 60%

144 FPS target, 7 ms workload

Frame time ≈ 6.94 ms
Headroom ≈ −0.06 ms (over budget)

Deep dive

This frame time calculator converts FPS into milliseconds per frame and compares it to your workload. Enter FPS and per-frame work time to see headroom and budget usage.

Use it to keep games, animations, and realtime dashboards smooth by leaving buffer for spikes. If headroom goes negative, reduce workload or lower the target FPS.

FAQs

Why is headroom negative?: It means your workload takes longer than the frame budget. Lower the workload or frame rate to prevent drops.
Does this account for GPU/CPU split?: It treats your workload as a combined number. Profile CPU and GPU separately if you need deeper insight.
How much headroom should I leave?: Aim for at least 10–20% free to handle spikes, IO, and OS overhead without hitching.
Can I use this for VR/AR frame targets?: Yes. Enter your target (e.g., 72/90/120). VR benefits from more headroom to avoid discomfort.
Does vsync/VRR change the math?: Frame pacing still matters—work must fit within the frame time even with adaptive sync.

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