How to estimate a bathroom remodel, step by step

Arez AI guides · October 21, 2026 · 8 min read

A bathroom is the job that looks small and prices big. In 40 square feet you can have demolition, plumbing, waterproofing, tile, electrical, drywall, paint and fixtures, often with a different person doing each. Miss one of them and the job pays less than you thought, or nothing at all.

This guide walks through how to build a bathroom remodel estimate that holds up: the order to work in, what to count, how to price labor, and how to set markup. At the end is a complete example for a 5x8 hall bath.

1. Pin down the scope before you price anything

Most bad bathroom estimates are scope problems, not pricing problems. Before you write a number, answer these on site:

• Refresh or gut? A refresh keeps the tub and tile and changes fixtures, paint and lighting. A gut takes the room to the studs.
• Room size. Length, width and ceiling height. A 5x8 hall bath is 40 square feet of floor and roughly 80 to 100 square feet of tiled wall around a tub.
• What stays where. Moving a toilet or a drain is a different job from replacing it in place.
• The fixture list. Tub or shower, vanity width, toilet, fan, lights, mirror, accessories.
• Finish level. Builder-grade tile and a stock vanity, or large-format porcelain and a custom top.

Write the assumptions down. They go on the estimate so the client knows exactly what the price includes.

2. Break the job into sections by trade

Price in the order the job is built. It keeps you from skipping a trade and makes the estimate easy for the client to read:

1. Demolition and disposal
2. Plumbing rough-in and trim-out
3. Backer board and waterproofing
4. Tile, walls and floor
5. Electrical: fan, lighting, GFCI outlets
6. Drywall, paint and trim
7. Fixtures: vanity, toilet, mirror, accessories
8. Permit, protection and clean-up

If you sub out a trade, price it as one subcontractor line with the sub's number plus your markup, not as materials and labor.

3. Count materials, and add waste

Measure the tile areas separately: floor, tub surround, any wainscot. Then add waste. 10% is common for straight-lay tile; diagonal, herringbone or large-format tile needs 15% or more. Do not forget the consumables that turn into a second trip: thinset, grout, trim pieces, sealant, screws, membrane and tape.

For fixtures, price the actual model the client picked, or give two options with their own totals. "Vanity, $680" means more to a client than "fixtures allowance."

4. Price labor in hours, by task

Labor is where bathroom estimates go wrong. A lump-sum labor number hides the fact that tile alone can take three or four days. Estimate hours per task at the rate for that work:

• Setting a tub and finishing the plumbing trim-out
• Backer board, waterproofing and tile (usually the biggest block)
• Vanity, toilet, fan and accessories
• Drywall repair, paint and trim

Hours make the estimate checkable. After the job, compare the hours you priced with the hours your crew actually spent, and adjust next time.

5. Add the costs that are not materials or labor

Permit, dumpster or haul-away, floor protection, and any equipment rental. These are small lines that add up to several hundred dollars on a bathroom, and they are the first to be forgotten.

6. Set your markup, and know what margin it gives you

Markup and margin are not the same number. A 20% markup on cost gives you a 16.7% margin on the price. To find the markup for a target margin, divide the margin by one minus the margin: a 25% margin needs a 33% markup.

Apply your markup to materials, labor and other costs alike, so every part of the job carries overhead and profit.

7. Say what is not included

Rot under the tub, a cracked drain, knob-and-tube wiring behind the wall. You cannot see these until demolition. List them as exclusions and tell the client they would be a change order, priced and signed before the extra work starts.

Example: a 5x8 hall bath, full rebuild

Here is a complete estimate for the job below, with 20% markup. The prices are illustrative; use your own.

“5x8 hall bath. Gut and redo it: new tub with tile surround, tile floor, 30 inch vanity, toilet, fan. Austin.” Assumptions: framing open, plumbing stays in place; standard alcove tub; mid-range tile.

The total comes to $10,956: $3,420 in materials, 70 hours of labor ($5,010), $700 for permit and dumpster, and $1,826 of markup.

Checklist: what bathroom estimates miss most

• Waste on tile, and the trim pieces for the edges
• Waterproofing membrane and the time to install it
• Valve and trim (they are not included with most tubs)
• The fan duct to the outside, not just the fan
• Drywall and paint where the old fixtures came out
• Permit, dumpster, and protecting the floors on the way in

Doing it faster

Everything above is what an estimating app should do for you. In Arez you send a photo of the bathroom with the size, and it returns an itemized estimate built in this order, with your labor rates and markup, and the assumptions listed so you can correct them in a sentence. See how it works on the remodeling estimating app page.

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