Updated October 23, 2026. By MouseDPITest
Use a gaming calculator when you have a specific question: which vertical FOV matches a horizontal angle, how wide a screen is, or how long a download takes at a measured speed. The result is useful only when its units and assumptions match your setup.
The Gaming Calculators Hub contains six arithmetic tools. This guide gives a worked example for each, explains the limits and shows where mouse sensitivity belongs in the process. The examples are calculations, not measured game or hardware benchmarks.
Start with the setting you want to compare
| Question | Tool or check | Keep separate |
|---|---|---|
| Do two sensitivity setups have the same base product? | Same-game eDPI | Different game scales and ADS modes |
| What vertical angle corresponds to this horizontal FOV? | FOV calculator | Game-specific FOV conventions |
| What shape and physical size is the image? | Aspect-ratio and screen-size calculators | Bezel width, stand size and OS scaling |
| What distance does this site's suggestion produce? | Viewing-distance heuristic | Comfort, readability and health guidance |
| When might a download finish? | Download-time estimate | Installation, decompression and varying throughput |
| How long between the first and final required hit? | Ideal TTK calculation | Misses, armor, travel time and network delay |
Record mouse movement before changing display settings
Read the configured hardware DPI in the device's supported software or saved profile. eDPI is that DPI multiplied by base in-game sensitivity, and it is comparable within the same game's sensitivity scale. As an illustrative example, 800 DPI at 0.30 sensitivity and 1600 DPI at 0.15 both produce 240 eDPI. Verify the physical camera turn inside the actual game, including the input mode you intend to use.
The browser ruler tool answers a separate question: it estimates CSS cursor travel per physical inch under the current desktop and browser settings. Its viewport-coordinate input is not raw sensor data. Do not enter a scaled browser estimate into eDPI as though it were a certified hardware setting.
Save mouse DPI, sensitivity, FOV, resolution and input options before changing any of them. If you change everything together, a different result will not tell you which change caused it.
Convert FOV with the correct axis and aspect ratio
The hub accepts a horizontal FOV and an image width-to-height ratio, then returns the corresponding vertical FOV for a rectilinear projection. Its geometry is vertical = 2 × atan(tan(horizontal ÷ 2) ÷ aspect ratio), with angles converted between degrees and radians during the calculation.
For a worked example, enter horizontal FOV 90, width 16 and height 9. The vertical result is about 58.7 degrees. A game's slider labeled 90 might refer to vertical FOV, horizontal FOV or a reference aspect ratio, so check that game's documentation before using the result.
Use the rendered image's aspect ratio, including any letterboxing or cropping, rather than automatically using the panel's native resolution. Matching an angle does not establish equal sensitivity, equal scope behavior or equal visual motion between games. Test the result in the actual mode you play.
Reduce a resolution to its aspect ratio
Enter pixel width and height into the aspect-ratio calculator. For 2560 × 1440, dividing both numbers by 160 gives 16:9. The decimal ratio is about 1.778. This describes shape, not pixel density or physical screen size.
A useful edge case is 3440 × 1440: its exact reduced ratio is 43:18, about 2.389. Use the actual dimensions in calculations instead of treating a broad display category label as an exact ratio. If the game renders a smaller viewport or stretches an image, record those dimensions separately.
Calculate screen width and height
The screen-size calculator uses diagonal size and aspect ratio to calculate a rectangular image's width and height. For diagonal d and ratio w:h, width is d × w ÷ sqrt(w² + h²), with the corresponding expression for height.
A 27-inch 16:9 image is about 23.5 inches wide and 13.2 inches high. Those dimensions describe the image area, not the complete monitor enclosure. Check the manufacturer's cabinet and stand dimensions before deciding whether the monitor fits a desk or shelf.
Resolution is a separate input when calculating pixel density. A 2560 × 1440 image across a 27-inch diagonal has about 108.8 pixels per inch, calculated from the pixel diagonal divided by physical diagonal. The PPI calculator performs that calculation. PPI does not establish mouse DPI or make a browser CSS pixel equal one physical screen pixel.
Treat viewing distance as an adjustable suggestion
The hub's viewing-distance tool applies a site heuristic to screen size and PPI. It is not a validated comfort, ergonomic or visual-acuity standard. With 27 inches and 109 PPI, the current formula gives a rounded 23-31-inch suggestion; that is an example of its output, not an independently established optimum.
Use readable text, your actual desk and a comfortable position to assess the setup. Adjust application zoom or OS scaling if necessary and record the new configuration. A calculator's range should not override a setup problem you can directly observe. For professional ergonomic or health advice, consult an appropriate qualified source rather than this heuristic.
Estimate downloads using throughput, not a plan label
The download calculation uses decimal GB and megabits per second: seconds = GB × 8000 ÷ Mbps. An 85 GB download at a constant 300 Mbps takes about 2267 seconds, or 37 minutes 47 seconds, before overhead.
Watch the units. A download client showing megabytes per second uses bytes, while Mbps uses bits; eight bits make one byte. If the client reports 25 MB/s using decimal units, that corresponds to 200 Mbps for this calculation. Use observed sustained throughput where possible, and distinguish GB from binary GiB if the client uses the latter.
This estimate excludes installation, decompression, pauses and changes in speed. If the download slows halfway through, recalculate the remaining size at the observed rate instead of treating the first estimate as a promised finish time.
Read TTK as an ideal interval between hits
The TTK calculator assumes constant damage per hit, fixed rounds per minute and every shot hitting. It calculates required hits by rounding health ÷ damage upward, then times the gaps between the first and final hits:
TTK in milliseconds = (required hits − 1) × 60000 ÷ RPM.
With 100 health, 30 damage per hit and 600 RPM, four hits are needed. There are three 100 ms gaps, so the result is 300 ms. One hit sufficient to defeat the target gives a zero interval in this model; it does not mean zero input delay or instant projectile travel.
Armor, different hit locations, range falloff, burst spacing, reloads, misses and game-specific damage rules can invalidate those inputs. Use damage and rate values verified for the game's current version. The tool is useful for arithmetic comparisons under its assumptions, not as a live weapon ranking.
Keep a repeatable setup record
- Write the question you want the calculation to answer.
- Record the current settings and verify units before entering values.
- Save the result together with its assumptions, not just the final number.
- Change one setting and check the outcome in the application that uses it.
- Restore the baseline if the change does not solve the original problem.