Learn how to display and check FPS in MSFS, X-Plane, DCS, FSX and Prepar3D, then read frame time and test performance accurately.
To display FPS in a flight simulator, use the simulator’s built-in frame-rate counter where available; otherwise enable a platform or graphics-driver overlay. Check it in a representative aircraft, location and camera view for at least a minute, and watch frame time as well as average FPS because short spikes cause visible stutters.
How do I turn on the built-in FPS counter?
Use the simulator’s own counter first because it can often show CPU, GPU and simulation timing that a basic overlay cannot.
| Flight simulator | How to display FPS | Useful detail |
|---|---|---|
| Microsoft Flight Simulator 2020 or 2024 on PC | Enable Developer Mode in the simulator settings, then open the developer toolbar and select Options followed by Display FPS. | The display can identify whether the main thread or GPU is limiting performance. Our step-by-step MSFS counter guide explains its timing and bottleneck readouts. |
| X-Plane 11 or 12 | Open Settings, select Data Output, and enable the cockpit display for the frame-rate data row. | X-Plane reports actual and simulation frame rates along with CPU and GPU frame times. |
| DCS World | Use the assigned FPS-counter command, commonly Right Ctrl + Pause/Break with the default controls. | If the shortcut does nothing, search the control assignments for the FPS command; compact keyboards may require an Fn key. |
| FSX | Press Shift + Z repeatedly until the red information text includes frame rate. | The shortcut cycles through several information displays, so one press may not show FPS. |
| Prepar3D | Many versions use Shift + Z to cycle the information text. Check the control assignment if that shortcut has been changed. | The built-in reading is preferable when diagnosing Prepar3D itself rather than an external overlay. |
Menu names and key assignments can change between simulator releases. If the expected shortcut fails, search the simulator’s controls for FPS, frame rate or information text before assuming the counter has been removed.
What can I use if there is no built-in FPS display?
On a Windows PC, a platform or graphics-driver overlay provides a general FPS counter for almost any flight simulator.
- Platform overlay: If the simulator is launched through Steam, enable its in-game FPS counter. Windows users can also open Xbox Game Bar, display the Performance widget and pin it over the simulator.
- Graphics-driver overlay: Enable the performance overlay supplied with your GPU software. Depending on the driver, this may add frame time, GPU utilisation and latency alongside FPS.
- Use only one counter while testing: Multiple overlays consume a small amount of processing time and make screenshots difficult to interpret.
Console editions normally do not expose the same developer counters available on PC. A television’s refresh-rate or VRR display is not a reliable FPS counter: it reports the output signal and may not reveal repeated frames, frame generation or internal rendering rate.
What do FPS and frame time mean?
FPS measures how many frames are produced each second, while frame time shows how long each frame takes and exposes brief interruptions more clearly.
| Frame rate | Approximate frame time |
|---|---|
| 30 FPS | 33.3 ms |
| 60 FPS | 16.7 ms |
| 90 FPS | 11.1 ms |
A steady 30 FPS can feel better than an average of 45 FPS that repeatedly falls into the twenties. The right target also depends on the display, aircraft and whether VR is being used; our explanation of what counts as good flight-simulator FPS covers those trade-offs.
Where a built-in counter separates CPU and GPU time, the larger value generally identifies the bottleneck. High CPU or main-thread time points towards traffic, complex aircraft systems, scenery detail or simulation workload. High GPU time points towards resolution, anti-aliasing, clouds, shadows and other graphics settings.
How should I check flight-simulator FPS accurately?
Test FPS in a repeatable flight rather than in the main menu, loading screen or an empty external view.
- Choose a demanding but realistic scenario: Load the aircraft, airport, weather, traffic level and cockpit view that you normally use.
- Let initial loading settle: Wait for major scenery and aircraft loading to finish, but do not ignore recurring pauses caused by normal scenery streaming.
- Measure for at least 60 seconds: Observe typical FPS, the lowest repeatable dips and frame-time spikes. A single minimum recorded during loading is not representative.
- Change one setting at a time: Fly the same route, camera angle and conditions after each adjustment. Otherwise the comparison is invalid.
- Test the limiting situation: Check the cockpit on the ground at a busy airport as well as the cruise. Performance can shift from CPU-limited to GPU-limited during the same flight.
Once the limiting component is clear, use our simulator-wide FPS optimisation steps rather than lowering every graphics option indiscriminately.
Why do two FPS counters show different results?
Different counters may measure different points in the rendering pipeline, so small discrepancies are normal and large ones often involve frame generation, VR reprojection or different sampling periods.
- Frame generation: An engine counter may report the underlying rendered FPS while a driver or presentation overlay counts generated frames too.
- VR: The desktop mirror does not always represent headset performance. Use an in-headset performance display where possible, and check whether reprojection is locking output to a fraction of the headset refresh rate.
- V-sync and FPS limits: A reading fixed at 30, 60 or another regular value may simply be following a cap or display refresh rate.
- Averaging: One overlay may update several times per second while another reports a longer rolling average, hiding short dips.
Use the same counter for before-and-after comparisons. If FPS looks high but motion still judders, the likely problem is inconsistent frame delivery, camera pacing or display synchronisation; see our guide to diagnosing choppy simulation at high FPS.