Understanding your result
The headline is the total cost of the supplies at the price level you chose, and the sub-line is the number of different items. The three figures show the counts that scale with the job: roller covers, rolls of tape and drop cloths.
The table is the list itself, one line per item with the quantity and the cost, then the price-level multiplier and the total. The shopping list at the bottom repeats it in store order with the unit price and a note on why each quantity is what it is. Print it with the button under the result.
Supplies are a fixed cost that does not shrink much for a small job, which is why they matter most on a single room. The paint cost calculator takes this total as its supplies line; the DIY versus hire calculator takes it with the paint as the cash cost of doing the job yourself; and the leftover paint planner deals with what is left in the cans when you are finished.
How we calculate this
The counts follow how the items are used. A roller cover carries one colour, and on a single colour it lasts about 2 gallons before it mats; the tray liner is changed with it. Each colour needs its own brush for cutting in, because cleaning a brush between colours on the same day is slower than buying a second. Tape goes on both edges of a trim run if both the wall and the trim are being painted. A drop cloth of 9 × 12 ft covers 108 sq ft of floor.
The unit prices are typical mid-range prices at US home-improvement stores in 2025, and the price level multiplies them by 0.7 or 1.5. The fixed kit (frame, tray, mini roller, filler, caulk, sundries, pole) is counted once whatever the job size. The room painting guide explains where each item is used in the order of work, and the standard sizes page lists the roll and cloth sizes behind the arithmetic.
The assumptions behind the numbers
| Assumption | Default | Where it comes from |
|---|---|---|
| Roller cover | one per colour and per 2 gallons, $5 | Typical 9 in, 3/8 in nap cover, 2025 US retail |
| Brush | one per colour, $12 | 2 in angled sash brush, mid-range |
| Painter’s tape | 60 yd (180 ft) roll, $7 | Standard roll length on 1.41 in tape |
| Drop cloth | 9 × 12 ft, $10 canvas-blend | Standard size; plastic about $4, heavy canvas about $15 |
| Extension pole | $20 | 4–8 ft telescoping pole |
| Ladder | $40 a day rental | Typical tool-rental counter price; not scaled by price level |
| Price levels | budget 0.7, mid 1.0, professional 1.5 | Site estimate of the spread between store-brand and premium lines |
Assumptions last reviewed October 8, 2026.
The calculator does not include paint, primer, cleaning products for walls, sprayer rentals or protective equipment beyond rags, and it does not know what you already own. Strike out what is in the garage before you shop; the total shrinks accordingly. The break-even guide explains why the supplies are a larger share of the cost on a small job than on a large one.
Two worked examples
One room, two colours, ceiling included
988 sq ft of wall and ceiling, 96 ft of trim to tape, 168 sq ft of floor, 5 gallons of paint, two colours, an extension pole, mid-range prices.
- Roller covers: max(2, 5 ÷ 2) = 3, and 3 liners
- Brushes: 2; tape: 96 × 2 ÷ 180 = 1.07, so 2 rolls; drop cloths: 168 ÷ 108 = 1.56, so 2
- Fixed kit: frame, tray, mini roller, filler, caulk, sundries, pole
- Total: $153.50 for 12 items
About a third of that, the frame, tray, pole and brushes, is still there for the next room. A single-colour room on a budget with no taping, no floor to cover and no ceiling, at 1 gallon, comes to $52.15.
A whole house at professional prices
2,900 sq ft of walls and ceilings, 400 ft of trim, 900 sq ft of floor, 26 gallons, four colours, a ladder rental, professional level.
- Roller covers: max(4, 26 ÷ 2) = 13, and 13 liners
- Brushes: 4; tape: 400 × 2 ÷ 180 = 4.4, so 5 rolls; drop cloths: 900 ÷ 108 = 8.3, so 9
- Total: $607.75 for 13 items, including the $40 ladder rental
The note on jobs over 10 gallons applies: a 5-gallon bucket with a grid replaces the tray and most of the liners, and an 18 in roller halves the rolling time.
Where to find your inputs
Wall and ceiling area. From the wall paint, ceiling paint or square footage calculators; it is used for context and the pole.
Trim to tape. The baseboard and casing lengths from the trim calculator, plus the ceiling line if you tape it rather than cutting in.
Floor area. Length times width of the rooms; furniture moved to the middle still needs covering.
Paint to be applied. The total of every product from the quantity calculators; it sets the covers and liners.
Colours. One for each wall colour, ceiling colour and trim colour.
Common mistakes
- One roller cover for two colours. Wash it and it will not be dry for the second colour today.
- Plastic drop cloths underfoot. They slide on hard floors and wet paint sits on them. Canvas on the walking path.
- Cheap brushes for cutting in. A brush that sheds and splays costs more in time than the price difference.
- Forgetting filler and caulk. Prep is half the job and needs its own kit.
- Buying a ladder for one job. Rent it unless you will use it again.
- Not checking the garage first. Half the list is reusable from the last job.
Questions people ask
- What supplies do I need to paint a room?
- A roller frame and two or three covers, a tray and liners, a 2 in angled brush for each colour, a mini roller, painter's tape for the trim, drop cloths for the floor, filler with a putty knife and sanding sponge, caulk, and rags and stir sticks. An extension pole if you are doing the ceiling. For one room at mid-range prices that comes to about $150.
- How many roller covers do I need?
- One per colour, and one per 2 gallons of paint on a single colour, because a cover loaded with a gallon or two starts to mat and shed. A room with two colours and 5 gallons in all takes three covers. Wash-and-reuse works for latex if you clean them the same day.
- How much painter's tape do I need?
- Both edges of every run of trim you tape, divided by the length of a roll. A 60 yd roll is 180 ft, so 96 ft of baseboard and casings taped on both edges is 192 ft, two rolls. Many painters cut in freehand on the ceiling line and tape only the trim.
- How many drop cloths for a room?
- Enough to cover the floor of the room, at 108 sq ft for a 9 × 12 ft cloth. A 12 × 14 room is 168 sq ft, two cloths. Canvas cloths are reusable and do not slide; plastic ones are cheap and slippery, fine under furniture but not underfoot.
- What is the difference between the price levels?
- Budget uses store-brand covers and brushes and plastic cloths, at about 70% of mid-range. Professional uses woven covers that shed less, premium brushes that cut a cleaner line and canvas cloths, at about 150%. Rentals are priced as the rental counter charges at every level.
- Is any of this reusable?
- Most of it. The frame, tray, pole, putty knife, caulk gun and a good brush last for many jobs if they are cleaned. The consumables are the covers, liners, tape, filler and caulk, which is why a second room costs much less than the first.