Bathroom renovation cost calculator
A budget range for your bathroom, built from published New Zealand cost bands. Every band shows where it came from, whether the source stated GST, and the date we read it. It is free and it is not a quote.
A typical New Zealand bathroom renovation costs about $22,000 excl. GST, with most mid-range jobs between $15,000 and $35,000 (CheckMyBuilder, July 2026). Where yours sits depends on the scope, the size of the room and the region, so this works on those three rather than on a rate per square metre.
1. Your bathroom
2. What goes in
excl. GST · $25,300–$61,400 incl. GST · reference BR-1GHX5E
A general guide, not a quote. It is built from published cost bands, not from a look at your room.
How that number was built
- Mid-range: new tiles, upgraded fittings, partial layout change$15,000–$35,000excl. GST · CheckMyBuilder, bathroom renovation cost guide (updated July 2026), checked 16 Sept 2026
- Tiled shower — shown separately, already inside the scope band aboveincludedGST status not stated by the source · Superior Renovations, bathroom renovation cost Auckland, checked 16 Sept 2026 · Published range for this on its own: $1,550–8,250. It is not added again here.
- Region factor: Auckland × 1.27$19,100–$44,500The factor is that region's typical job divided by CheckMyBuilder's New Zealand typical of $22,000.
- Contingency, 15–20%$2,900–$8,900Superior: "Always add 15–20% contingency." Shown as its own line, because it gets spent.
- Total$22,000–$53,400excl. GST. With GST at 15%: $25,300–$61,400. Where a source does not state GST status, the row above says so and the figure is used as published.
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Bands last checked 16 Sept 2026. Figures marked $are New Zealand dollars. Re-checked quarterly.
The method, in full
Superior Renovations says per-square-metre rates work badly for bathrooms, and explains why: fixed trade costs in Auckland, at plumber, electrician and tiler rates of $90–120 an hour, account for $10,000–15,000 regardless of the size of the room. What scales with size is tiles and membrane, and on a 5 m² room versus a 10 m² room that is perhaps a $1,000–2,000 difference, not the $10,000 people expect. So this calculator does not use a per-m² rate.
1. The base band
For a standard or large room, the base is CheckMyBuilder's tier for the scope you picked: budget $8,000–15,000, mid-range $15,000–35,000, premium $35,000–70,000, all excl. GST, updated July 2026. A large room lifts the bottom of the band 40% of the way toward the top, because a larger room sits in the upper part of a published range rather than at its floor.
For a small room, under about 5 m², it uses Superior Renovations' New Zealand-average small-bathroom bands instead: minor upgrade $4,000–8,000, full renovation $15,000–25,000, custom with layout changes $25,000–35,000. That page does not state a GST status, so neither do we.
2. Adjusters
Moving the toilet or the shower adds $2,000–6,000, floor-to-ceiling or premium tiling adds $2,000–10,000, and custom joinery instead of an off-the-shelf vanity adds $1,500–5,000 (all CheckMyBuilder, excl. GST). Half-height tiling takes half of the published floor-to-ceiling band. The shower is shown as its own published line but is not added again, because the scope band already contains a shower.
3. Region
The factor is that region's typical job divided by the New Zealand typical of $22,000, all from CheckMyBuilder: Auckland $28,000 (×1.27), Wellington $24,000 (×1.09), Christchurch $22,000 (×1), Rest of New Zealand $20,000 (×0.91).
4. Contingency
15–20%, shown as its own line rather than buried in the total, because Superior Renovations recommends exactly that and because on an older house it gets spent. Their worked example: a $30,000 budget should have $4,500–6,000 set aside.
5. GST
The headline range is excl. GST, which is how CheckMyBuilder publishes. The incl. GST line applies 15%. Where a Superior band is used, the row says the source did not state GST status and the figure is used as published rather than adjusted on a guess.
What it cannot know
What is behind your tiles. Whether the subfloor is sound. Whether the waste is where you think it is. Whether there is asbestos in the vinyl. Whether the wall you want gone is load-bearing. Those are what the measure-and-design visit is for, and they are why a range from a website is a starting point rather than a number to budget against.
Questions about the calculator
How does this calculator work?
It uses scope × room size × region, not a rate per square metre. Superior Renovations makes the point itself: fixed trade costs of $10,000–15,000 in Auckland apply regardless of bathroom size, so a per-m² rate gives a small room an answer that is badly wrong. The base band comes from CheckMyBuilder's three tiers for a standard room, or Superior's small-bathroom bands for a room under about 5 m². Adjusters, the region factor and the contingency are each their own line, with their own source.
Where does the region factor come from?
It is CheckMyBuilder's own regional typical divided by its New Zealand typical of $22,000: Auckland $28,000 gives 1.27, Wellington $24,000 gives 1.09, Christchurch $22,000 gives 1.00 and regional New Zealand $20,000 gives 0.91. Nothing is invented; the division is shown on the result.
Is this a quote?
No. It is a general guide built from published cost bands, not from a look at your room. It cannot know what is behind your tiles, whether the subfloor is sound or whether the waste is where you think it is. A measure-and-design visit is what turns it into a line-item budget for your actual bathroom.
Why is the range so wide?
Because the published bands are wide, and narrowing them without evidence would be making things up. CheckMyBuilder's mid-range tier alone runs $15,000–35,000. A visit narrows it; a website cannot.
Does it include GST?
It shows both. CheckMyBuilder states its figures exclude GST. Superior Renovations does not state a GST status on its page, so where a Superior band is used the row says so and the figure is used exactly as published. The incl. GST line applies 15% to the excl. GST total.
What isn't in it?
Asbestos testing and removal, council consent fees and levies, engineering where a wall turns out to be load-bearing, and anything outside the bathroom footprint. The calculator flags consent and asbestos rather than pricing them.