Keycap Profile Angle Calculator
Choose a keycap profile and case angle to see per-row top heights, effective typing angle at each row and a palm support recommendation.
Tool Operation Area
Per-row geometry
| Row | Cap height | Internal slope | Effective angle | Height above plate |
|---|---|---|---|---|
| R1 | 9.4 mm | 0.0° | 6.0° | 9.4 mm |
| R2 | 9.9 mm | 1.5° | 7.5° | 11.9 mm |
| R3 | 11.1 mm | 3.6° | 9.6° | 15.1 mm |
| R4 | 12.6 mm | 4.5° | 10.5° | 18.6 mm |
Suggested palm rest height: 7.9 mm above the desk, level with the front edge of the home row. Keep total effective angle at the top row under 15 degrees to avoid wrist extension.
Working Principle
Keycap profiles differ in two ways: absolute height above the plate and whether rows are sculpted. Uniform profiles such as DSA and XDA use the same cap on every row, so the only slope your fingers feel is the case angle. Sculpted profiles such as Cherry, OEM and SA raise the far rows and lower the home row, adding an internal curvature on top of the case angle. Cherry profile row 1 sits near 9.4 mm at the front edge while row 4 reaches about 12.6 mm; SA is far taller, roughly 12 mm to 16.5 mm, which is why SA sets feel dramatically different on the same board. The effective angle presented to your fingertip at a given row is the case angle plus the local slope created by the height difference between adjacent rows, and since rows are one key unit apart the slope is the arctangent of the height difference divided by 19.05 mm. Adding a 6-degree case typing angle to a sculpted profile can push the top row past 15 degrees of effective incline, which forces wrist extension unless the palm is supported. Ergonomics research on keyboard posture consistently favours a neutral or slightly negative wrist angle, so the tool converts fingertip height at the home row into a suggested palm rest height: broadly, the rest should meet the underside of the palm at the height of the home row front edge, not above it.
How to Use
- 01Select the keycap profile you own or plan to buy.
- 02Enter the case typing angle. Most cases are 5-7 degrees; check the vendor page or measure with a phone inclinometer.
- 03Optionally add a front-height offset if your case has a raised front bezel.
- 04Read per-row heights, effective angles and the palm rest suggestion.
- 05Beginner note: profile heights are measured from the top of the plate, not the desk. Tall cases add to every figure equally.
FAQ
Are these heights exact for every keycap manufacturer?
They are industry-typical values. Individual sets vary by roughly 0.3 mm because of mould and material differences between ABS and PBT.
Which profile is best for a first build?
Cherry and OEM are the safest, since they are sculpted, widely available and moderate in height. SA and MT3 are much taller and change typing feel substantially.
Does a uniform profile need a palm rest?
Less often, because there is no internal slope, but if the case angle exceeds about 7 degrees a rest still helps keep the wrist neutral.
Why does my top row feel harder to reach than the calculation suggests?
Reach depends on finger length and keyboard distance from the desk edge, not just height. Pair this tool with the Typing Ergonomics Calculator.
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