How to Configure G-Sync and Calculate Refresh Rate Frame Budgets
Calculate exact frame budgets in milliseconds across 60Hz to 540Hz displays, calculate optimal G-Sync/FreeSync framerate caps (-3 rule), and analyze frametime jitter.
Display Refresh Rate & Frametime Budget Calculator
Calculate exact millisecond frame budgets, the G-Sync / FreeSync -3 FPS cap rule, and frametime variance for tear-free, ultra-low-latency competitive gaming.
Frametime Variance & Stutter Jitter Calculator
Enter your target average and 1% low framerate to evaluate frametime stability and frame drop penalty.
Why cap 3 FPS below refresh rate? When framerate reaches 144/240Hz, G-Sync turns off and standard V-Sync buffer queuing activates, injecting 15-35ms of display buffer lag. Capping 3 FPS below keeps G-Sync active 100% of the time with zero tearing.
How to Configure G-Sync and Calculate Refresh Rate Frame Budgets
Select Display Refresh Rate
Choose standard 60Hz, 144Hz, 240Hz, 360Hz, 540Hz, or enter custom Hz.
Review -3 FPS Cap Rule
Apply the optimal FPS ceiling to keep variable refresh active without V-Sync buffer lag.
Check Frametime Variance
Input average and 1% low FPS to calculate millisecond frametime variance.
Frequently Asked Technical Questions
Why must I cap framerate 3 FPS below monitor refresh rate?
Capping 3 FPS below refresh rate prevents G-Sync from disengaging and activating traditional V-Sync buffer backpressure, which adds 15–35ms of display lag.
What is a good frametime budget at 240Hz?
At 240Hz, each frame must complete within 4.17ms. Keeping frametime variance under 3.0ms ensures completely smooth, tear-free motion.