Miterwright Trim Calculator

Miterwright is a finish carpentry calculator for finish carpenters, cabinetmakers and installers, tile setters, deck builders and serious DIYers. It works like a hardware calculator: a dark walnut chassis, real keys and a clear LCD, with each answer labelled so you know what you are reading.

EQUAL SPACING
• Balusters, pickets or any equal pieces across a span: type the span and the piece width (a turned baluster at its thinnest) and get the count from your maximum gap (72 in span, 1.5 in balusters, 4 in gap: 13 pieces)
• Then the gap (3 3/4 in), the on-center distance (5 1/4 in) and the maximum gap used; every gap comes out under the maximum, never on it
• Marks: the distance from the start of the span to the near edge of every piece (3 3/4, 9, 14 1/4 and on to 66 3/4). Lay out from the marks: the gap shows rounded to the sixteenth, and a spacer cut to it adds that rounding at every gap
• Or type the count, the on-center distance or an exact gap and solve the rest (an end gap over the maximum is flagged)
• Gaps at both ends, pieces flush at the ends, or half gaps at the ends

CROWN AND MITERS
• Compound miter and bevel for crown molding from the spring angle and the wall corner: 38° spring on a 90° corner is miter 31.62°, bevel 33.86°, cut flat
• Cut nested (crown upside down against the fence): the miter is 90° minus half the corner and the bevel is 0
• Spring presets for 52/38 and 45/45 stock crown (38° and 45°, measured between the back of the molding and the wall) or any spring angle you type, and any corner from 1° to 179°, outside corners too (a 135° bay window: miter 14.31°, bevel 17.55°)
• Plain miters for picture frames and polygons: type the corner and get the saw setting (an octagon's 135° corner: 22.5°)
• Corner angle from measurements: two wall lengths and the diagonal (24 in, 24 in and 44.35 in across: about 135°)

CABINET DOORS
• Type the opening width and height and get overlay door sizes: a 15 × 30 in opening with 1/2 in overlay takes a 16 × 31 in door
• A pair of doors: the width of each leaf, with the 1/8 in center gap taken out (7 15/16 in)
• Inset doors with a reveal all round (14 7/8 × 29 7/8 in at a 1/16 in reveal)
• Set your own overlay and reveal

TILE AND DECK LAYOUT
• Full tiles along a run and the last cut, with the joint counted (120 in run, 12 in tile, 1/8 in joint: 9 full tiles and a 10 7/8 in cut)
• Centered layouts: a tile or a joint on the midpoint, with the end cuts and a SLIVER flag when a cut is under half a tile
• Deck boards and planks: the same with a board width and gap (144 in of 5.5 in boards with 3/16 in gaps: 25 boards and a 1 13/16 in cut)
• Quantities: tiles for an area plus 10 or 15 percent waste (120 sq ft of 12 in tile: 118 tiles, 130 with 10 %, 136 with 15 %)

WORKS THE WAY YOU DO
• Feet, inches and fractions to the sixteenth, or millimetres
• A results strip shows every solved value at once
• 10 memories, a tape of your calculations, reference tables (compound miter settings, maximum guard openings by code, door defaults, tiles per area) and a key guide
• Export a job strip: the tape with inputs, stamped and ready to attach to a lift plan, sign-off or take-off, as text or PDF

FREE TO TRY, THEN UNLOCK ONCE
Free to try: every feature for 7 days. Then unlock Pro once — no subscription, no ads, works offline.

PRIVATE BY DESIGN
Works offline, no account, no data collected.

How it's calculated: the formulas and tables behind every result, at https://wrightcalc.app/miterwright/

Questions or feedback: support@wrightcalc.app

CHECK BEFORE YOU CUT. Check guard openings against the code that applies where you build, and cut a test piece first. Miterwright works with what you enter; the developer accepts no liability for loss, damage or injury arising from use.