Dado Calculator
A dado calculator should start from the actual mating part thickness, fit allowance and cut depth. The working dado and groove calculator adds wall marks, centerline, remaining thickness and cutter passes.
Slot width
The target slot width is the actual mating part thickness plus the chosen fit allowance.
slot_width = mating_part_thickness + fit_allowance
Depth screen
The calculator reports depth ratio and remaining back thickness so shallow and aggressive cuts are visible before setup.
Cutter passes
If the cutter is narrower than the slot, the calculator spaces multiple passes. Final tear-out control, climb cuts and fence setup remain shop decisions.
Frequently asked questions
Does this work for grooves too?
Yes. The working calculator covers both dado and groove layout marks with the same slot-width math.
Can it calculate router passes?
Yes. Enter cutter width and maximum step-over to get pass count and centerline spacing.
Related pages
- Dado and groove calculator - working slot width, depth and pass layout calculator.
- Mortise tenon calculator - adjacent woodworking joint layout.
- Drawer box calculator - cabinet drawer sizing workflow.
- Shelf sag calculator - check shelf stiffness after dado layout.
- Cut list calculator - prepare shelf and divider stock before slots.