About the site
About Bathroom Calculator
BathroomCalculator.net is a free, independent planning tool built around one refusal: we don't do black-box estimates. Every bathroom number this site produces comes from an anchored base rate, printed scope multipliers, itemized trade labor and a visible contingency — so the figure you plan with is a figure you can take apart.
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remodel scopes modeled
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labor trades itemized
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upgrade toggles, priced openly
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sign-ups required
Why we built this
Most bathroom remodeling decisions are made twice: once in a spreadsheet nobody checks, and once at the kitchen table when the contractor's bid arrives and the number is 40% higher than the blog post promised. We started this site after watching that scene repeat too many times — a homeowner with a five-figure budget, three contradictory online estimates, and no way to see which assumptions sat behind any of them. One calculator said $8,000. Another said $20,000. Neither explained itself, and both were quietly estimating a different room: one priced a 35 sq ft powder room, the other a 100 sq ft primary bath with the plumbing moved.
The problem was never a shortage of bathroom calculators. It was a shortage of calculators that show their work. Bathroom estimating has real structure — a base installed cost per square foot, scope multipliers, finish tiers, regional labor rates, itemized trade labor, waste factors, contingency — and almost none of that structure was visible in the tools people actually use. So we built one that is: every input stays on the left, every dollar lands on the right, and every intermediate number sits where you can audit it.
We are equally clear about what this site is not. It is not a lead-gen form wearing a calculator as a costume. It does not sell fixtures, take affiliate commissions on tile, or hand your inputs to contractors who will call you for a week. It is a focused planning tool: one estimation engine, maintained carefully, wrapped in guides that explain the reasoning — why waterproofing is priced even though it never photographs well, why pre-1980 homes carry a risk buffer, and why the paint line shrinks when the tile line grows. Everything runs free, in your browser, with no account, because an estimator behind a registration wall is an estimator most people will never finish using.
What the site does, in three moves
One estimation engine powers everything, but a remodel decision has three distinct moments: getting the number, understanding the number, and sharpening the number with the details that separate two quotes on the same room.
The core engine
Estimate
Four scopes — Refresh, Pull & Replace, Tub-to-Shower, and Full Gut — priced against an exact square footage slider instead of dead Small/Medium/Large buckets. A 65 sq ft bath is priced as 65 sq ft, with finish tiers and regional multipliers applied to the whole labor stack, not one convenient line.
Run an estimate →No black boxes
Decompose
Every estimate splits into labor by trade (eight itemized lines from tear-out to waterproofing), materials by category, permits, and contingency. Toggle DIY mode and the trades you self-perform are struck through with the savings badge updated live — nothing hides inside a lump sum you have to take on faith.
See the DIY math →Precision inputs
Refine
Beyond the headline number: shower and floor tile areas derived from your room, vanity width and countertop material pricing, plumbing reconfiguration with permit and dumpster line items, a pre-1980 rough-in risk buffer, and seven priced upgrade toggles from curbless showers to steam systems.
Explore the toolset →How an estimate is built, step by step
The engine runs a fixed chain — anchor, scale, itemize, price decisions, protect with contingency — and none of the steps are hidden. Here is the whole method in plain language, so you can sanity-check any output against your own reasoning.
- 01
Anchor to an audited base rate
The engine starts from a 2026 national installed-cost anchor: a standard 60 sq ft hall bath at Pull & Replace scope and mid-range finish, at roughly $285 per square foot installed. That anchor is cross-checked against published remodel cost surveys and contractor bid data rather than invented — it is the single number everything else scales from, so it gets the most scrutiny.
- 02
Scale by scope, not guesswork
Scope multipliers reset the budget around the work actually performed: Refresh runs about half of a pull-and-replace budget because surfaces change but nothing behind them does; Full Gut runs about 1.6× because studs, re-piping and re-waterproofing multiply labor. Each multiplier is fixed and printed, so you can verify what a scope change does to your own room.
- 03
Split labor into eight real trades
Labor is not one mysterious 50% slice. It is itemized into tear-out, plumbing rough-in, electrical, tile setting, flooring, painting, fixture setting, and waterproofing — each with its own share of the labor budget and its own DIY-eligibility flag. That split is what makes the Partial DIY mode honest: when you check a trade, the exact labor dollars leave the estimate.
- 04
Price the decisions separately
Layout changes, curbless showers, heated floors, steam systems, freestanding tubs, custom vanities and electrical scope each carry their own fixed dollar range, shown on the toggle itself. Plumbing reconfiguration additionally adds permit fees and dumpster costs, because moving a drain is a logistics project, not just an hour of plumber time.
- 05
Protect the estimate with contingency
A 10% contingency is added on top of the configured project, and pre-1980 homes get an extra $1,200–$2,500 rough-in and subfloor buffer. This reflects what actually happens behind tile in older homes: galvanized supply lines, corroded drains and soft subfloor are discovered mid-demo, and the estimates that pretend otherwise are the ones that turn into change orders.
Where our numbers come from
A calculator earns trust by showing its receipts. These are the standards and data families behind the tool's defaults — and the correction process that keeps them current.
NKBA planning guidelines
Room dimension defaults, vanity widths and fixture clearances used by the tool's dimension helpers follow National Kitchen & Bath Association planning standards — the same clearance targets professional designers use when they lay out a bath that actually works instead of one that merely photographs.
TCNA waterproofing methods
Wet-area construction assumptions — membrane over backer board, sloped pans, the tile area that gets netted out of the paint line — follow Tile Council of North America handbook methods. Waterproofing is priced as its own labor line precisely because lowball bids quietly omit it.
NEC 2023 electrical scope
The electrical rough-in toggle reflects code-minimum expectations for bathrooms: GFCI protection, dedicated circuits, receptacle placement and ventilation requirements from the current National Electrical Code cycle, so the adder represents what an inspector will actually ask for.
Published cost surveys
The base anchor and regional multipliers are calibrated against national remodel cost reports and trade rate surveys, then reviewed whenever a reader sends a better-documented source. Estimates are planning figures — your local market always wins, and the tool says so everywhere it matters.
Who it is for
A planning tool succeeds when it fits the person holding the tape measure. These are the four groups we design for — the engine serves all of them with the same formulas and the same printed assumptions.
Homeowners planning a first remodel
You have a room, a budget ceiling, and a strong suspicion that the internet is lowballing you. The calculator prices your exact square footage, shows what each scope decision costs, and hands you a printable breakdown you can hold against the first bid that arrives.
DIYers deciding what to self-perform
Flip to Partial DIY and check the trades you can realistically handle — tear-out, painting, flooring, even tile if you are confident. The savings badge updates live, and the trades that should never leave professional hands (plumbing rough-in, electrical, waterproofing) stay visibly priced.
Contractors and estimators
Use it as a neutral reference when a client's expectations and your quote diverge. Every toggle carries its own dollar range, so a conversation about budget becomes a conversation about scope line items instead of a negotiation conducted entirely in adjectives.
Designers and stagers
Finish-tier pricing (budget, mid-range, high-end) plus countertop materials from laminate to marble let you model what a client's taste actually costs before presenting options — and share links carry the exact inputs so everyone is looking at the same numbers.
How we work
Five working rules that decide what ships on this site — and what gets sent back for another pass.
Exact square footage, always
Bathrooms are the most size-sensitive room in the house — a 15% area error swings a five-figure budget. The slider runs from 20 to 250 sq ft and presets snap to the classic 35 / 60 / 100 / 140 sizes, but nothing forces your room into a bucket that does not fit it.
Every toggle shows its price
No checkbox changes the total by a hidden amount. Heated floor, curbless shower, steam system, plumbing moves — each displays its own dollar range before you commit it, because a decision you cannot price is a decision you cannot make.
Waterproofing stays in the bid
Membrane, backer board and slope-to-drain work are invisible in finished photos and therefore the first thing lowball estimates cut. This tool prices them as a named labor line, and the guides explain why removing them is how bathrooms fail.
DIY honesty over DIY optimism
The DIY toggle celebrates what self-performing genuinely saves — and refuses to pretend plumbing rough-in or electrical work is a weekend project. Permitted, code-bound trades stay in the estimate with their inspection logic intact.
Formulas where you can see them
The homepage prints the worked example with every intermediate step, and the engine uses the same math. An estimate you can audit line by line is worth more than a confident number you have to trust.
The site at a glance
The practical facts without scrolling: what it costs, what we store, and how your data is handled. Longer versions live in the privacy policy and terms of service.
- Cost
- Free. No accounts, no subscriptions, no paywalled results.
- Where it runs
- Entirely in your browser — inputs, saved estimates and print jobs never leave your device.
- Units
- Imperial and metric inputs supported, with smart parsing for feet-and-inches entry.
- Print & export
- One click produces a clean A4 quote sheet — navigation and ads hidden automatically.
- Saved estimates
- Stored in your browser's local storage only; deleting them takes one click and leaves no copy with us.
- Advertising
- May appear on the site, but never influences formulas, presets, or calculator behavior.
What's next
The estimation engine stays the flagship, but the same discipline — printed assumptions, itemized lines, honest contingency — is being extended across the whole remodel workflow. Nothing ships until its math is verified against industry standards and real trade practice.
🕒Timeline & sequencing plannerPlanned
Permit gates, tile cure windows, fixture lead times — a schedule view that shows why a two-week remodel takes six weeks of calendar.
🧾Bid comparison sheetPlanned
Paste in up to three contractor quotes and get a line-by-line variance report against your calculator estimate.
♿Aging-in-place modulePlanned
Grab bars, comfort-height fixtures, curbless entries — priced as a coherent accessibility package rather than scattered add-ons.
💧Water usage & efficiency comparerPlanned
Model fixture upgrades against WaterSense baselines to see the annual savings a high-efficiency remodel quietly adds.
Questions people ask about this site
Who is behind Bathroom Calculator?
A small independent team of remodel-industry writers, estimators and web builders who kept needing the same transparent tool and never found one. We maintain the engine, write every guide ourselves, and read every correction that arrives through the contact page. There is no contractor network, fixture retailer or affiliate program behind the site — that independence is what lets the numbers stay honest.
Why does this page not repeat the cost tables from the homepage?
On purpose. The homepage answers 'what will my remodel cost'; this page answers 'how does the tool work and who stands behind it.' Splitting the two keeps each page deep instead of duplicated — the cost matrices, worked examples and DIY comparisons all live where the calculator lives.
How current is the pricing data?
The base anchor reflects 2026 national installed-cost data and is reviewed against published remodel cost surveys on a quarterly cycle. Regional multipliers and material price ranges are starting points, not quotes — your local market, contractor tier and what demo uncovers will move the final number, which is exactly why every estimate ships with a range and a built-in contingency.
Can I trust the DIY savings badge?
It is conservative by design. When you check a trade in Partial DIY mode, the badge subtracts only that trade's itemized labor share — not materials, not tool rentals, not the value of your weekend. The guides walk through which trades are realistically self-performable and which ones fail inspection, void insurance, or leak inside walls for years.
Does the site work on mobile and can I share my estimate?
Yes on both. The calculator layout adapts to phone screens with the same inputs and outputs, and every calculation encodes into the page URL — bookmark it, text it to a partner, or hand the link to a contractor and it reopens with your exact configuration loaded.
Ready to price your bathroom?
Drag the size slider, pick a scope, toggle what applies to your room — and watch an auditable estimate build itself line by line.