Reference

Standard Sizes for Paint Estimating

Every standard size the calculators use when you give a count instead of a measurement, so you can see what a "door" or a "medium room" means and override it when yours is different.

Last updated

Why standard sizes

Estimating by counting is faster than measuring every opening, and on a typical house the errors cancel out: one window is bigger than the standard, the next is smaller. Every calculator that asks for a count of doors, windows or rooms uses the sizes below. If yours are very different, measure them and use the calculator’s area fields instead.

Openings taken out of walls

Opening Standard size Area taken out Metric Used by
Interior door 36 × 80 in 20 sq ft 1.86 m² Wall paint, whole-house, paint vs wallpaper, square footage
Window about 3 × 5 ft 15 sq ft 1.39 m² As above
Window, two-tone split 36 × 60 in, sill at 36 in split at the colour line Two-tone wall
Door, for wallpaper drops 3 ft wide one drop width 0.91 m Wallpaper rolls, paint vs wallpaper
Window, for wallpaper drops 3 ft wide half its width 0.46 m As above, because paper runs above and below

A patio door or a wide picture window is close to two standard openings. A fireplace opening is around 10 to 15 sq ft.

Trim, doors and windows as paint surfaces

Item Standard size Paint area Used by
Door, one face 36 × 80 in 20 sq ft, × 1.15 for raised panels, × 0.6 for French or glazed doors, × 1.6 for louvered doors Door paint
Door edges 1.75 in thick about 2.4 sq ft for the three visible edges Door paint
Door casing, both sides 17 linear ft per door about 16 sq ft Trim paint, project planner
Window casing 16 linear ft per window about 10 sq ft Trim paint, project planner
Window trim, small / standard / large 8 / 12 / 18 sq ft, × 1.5 with sashes Window trim paint
Exterior door trim 8 sq ft Exterior trim paint
Exterior window trim 6 sq ft Exterior trim paint
Exterior corner board 5.5 in wide, two faces per linear ft of height Exterior trim paint
Baseboard, deducted at doors 3 ft per door Trim paint, project planner

Rooms

Template Floor size Doors Windows Wall area at 8 ft Used by
Small room 10 × 10 ft 1 1 285 sq ft Whole-house, project planner
Medium room 12 × 14 ft 1 2 366 sq ft As above, painter cost
Large room 15 × 18 ft 2 2 458 sq ft As above
Bathroom 6 × 8 ft 1 1 189 sq ft As above
Hallway both sides, 3.5 ft wide one per 10 ft per linear ft Whole-house

Ceiling heights are entered rather than assumed; 8 ft (2.4 m) is the default, and 9 ft and 10 ft are common in newer and older houses.

Exterior items

Item Standard size Area Used by
Single garage door 8 × 7 ft 56 sq ft a face, × 1.15 raised panel, × 1.25 carriage style Garage door paint
Double garage door 16 × 7 ft 112 sq ft a face Garage door paint
Deck step 5 sq ft each Deck stain, porch floor
Deck railing 2 sq ft per linear ft, both sides Deck stain
Fence gate 4 ft (1.2 m) added to the fence length Fence stain
Gable width × height half the rectangle Exterior house, shed

Cabinets and furniture

Item Area per face Used by
Cabinet door 3.5 sq ft Cabinet paint
Drawer front 1.25 sq ft Cabinet paint
End panel 5 sq ft Cabinet paint
Face frame 2 in wide, per linear ft Cabinet paint

Wallpaper, tape, drop cloths and small containers

Item Size Used by
US double roll, standard 20.5 in × 33 ft, about 56 sq ft Wallpaper rolls, cost, paint vs wallpaper
US double roll, wide 27 in × 27 ft, about 61 sq ft As above
European roll 0.53 × 10.05 m, about 5.3 m² As above
Trim allowance per drop 4 in (10 cm) Wallpaper rolls
Wallpaper border spool 5 yd (15 ft) Wallpaper border
Painter’s tape roll 60 yd (180 ft) Two-tone, striped, supplies
Drop cloth 9 × 12 ft Supplies
Sample pot 8 fl oz (237 mL) Sample pots, accent wall
Spray paint can 12 oz, about 15–20 sq ft a coat Metal railing, furniture

US wallpaper is priced per single roll and sold in double rolls; a single roll is half a double roll. European rolls are priced and sold as one roll.

Sources and notes

Door and window sizes are the common US stock sizes (a 36 × 80 in exterior or interior door; a 3 × 5 ft double-hung window), and the 20 and 15 sq ft deductions are the figures used across painting estimators and manufacturers’ paint calculators. Wallpaper roll sizes are the standard US and European roll sizes printed on roll labels. Trim, cabinet, garage door and room figures are site estimates derived from those standard sizes and are stated as such on the calculator pages. Tape, drop cloth and container sizes are standard retail sizes.

Calculators that use this table

The guide measuring a room for paint explains when to count and when to measure.