Home Renovation Budget Calculator

Build a renovation budget room by room, with labour and a contingency that covers the surprises.

Renovation budgets fail in the same way every time: the materials are priced, the labour is forgotten, and the thing discovered behind the wall is not in the budget at all.

Enter the cost of each stage of the work and a contingency, and this calculator shows the total, what the contingency adds, and how the budget compares with the money you have set aside.

At a glance

What you enter: Materials, Trades and labour, Fixtures and fittings, Decoration and finishing, Structural work, Permits, surveys and professional fees, Waste removal, hire and delivery, Other costs, Rooms being renovated, Contingency, Money set aside
What you get: Realistic renovation budget, Subtotal before contingency, Contingency added, Left over, or still to find, Average cost per room
Formula shown: Yes - every step, right below your results.
Cost and privacy: Free, no account needed, and nothing you type is stored.

See worked examples ↓ Read the FAQ ↓ Share this calculator ↓

Materials

Trades and labour

Fixtures and fittings

Kitchen units, bathroom suite, flooring, lighting, appliances.

Decoration and finishing

Structural work

Walls, roof, windows, damp proofing, drainage.

Permits, surveys and professional fees

Waste removal, hire and delivery

Other costs

Storage, temporary accommodation, insurance, cleaning.

Rooms being renovated rooms

Contingency

Money set aside

Reset

Results are estimates for general information only - always verify with a professional or official source before acting on them.

How to use the Home Renovation Budget Calculator

1 Enter Materials
2 Enter Trades and labour
3 Enter Fixtures and fittings - Kitchen units, bathroom suite, flooring, lighting, appliances.
4 Enter Decoration and finishing
5 Enter Structural work - Walls, roof, windows, damp proofing, drainage.
6 Enter Permits, surveys and professional fees
7 Enter Waste removal, hire and delivery
8 Enter Other costs - Storage, temporary accommodation, insurance, cleaning.
9 Enter Rooms being renovated (rooms)
10 Enter Contingency
11 Enter Money set aside
12 Press Calculate. You get Realistic renovation budget, Subtotal before contingency, Contingency added, Left over, or still to find, Average cost per room, and every intermediate step stays visible under “How is this calculated?”
13 Change one number at a time to see what moves the result - that is usually the most useful thing a calculator can tell you.

Worked examples

Real numbers run through this calculator. Open any example to load it into the form above and change it.

A kitchen and bathroom at $43,355 against $40,000 saved

Two rooms with structural work, a 15% contingency, and a gap of $3,355 to find.

You enter

Materials: $9,000.00
Trades and labour: $14,000.00
Fixtures and fittings: $8,000.00
Decoration and finishing: $1,500.00
Structural work: $2,500.00
Permits, surveys and professional fees: $1,200.00
Waste removal, hire and delivery: $900.00
Other costs: $600.00
Rooms being renovated: 2 rooms
Contingency: 15%
Money set aside: $40,000.00

You get

Realistic renovation budget: $43,355.00
Subtotal before contingency: $37,700.00
Contingency added: $5,655.00
Left over, or still to find: -$3,355.00
Average cost per room: $21,677.50

The priced work comes to $37,700. A 15% contingency adds $5,655, so the realistic budget is $43,355, which is $3,355 more than the $40,000 set aside: your funds cover 92.3% of it. That is $21,677.50 for each of the two rooms, and labour is 37.1% of the priced work. Funding the gap over a year means saving $279.58 a month.

Open this example in the calculator →

Five rooms redecorated at $18,700 against $20,000 saved

Cosmetic work with no structural line and a 10% contingency, which fits the money available.

You enter

Materials: $4,000.00
Trades and labour: $6,000.00
Fixtures and fittings: $3,000.00
Decoration and finishing: $2,500.00
Structural work: $0.00
Permits, surveys and professional fees: $500.00
Waste removal, hire and delivery: $600.00
Other costs: $400.00
Rooms being renovated: 5 rooms
Contingency: 10%
Money set aside: $20,000.00

You get

Realistic renovation budget: $18,700.00
Subtotal before contingency: $17,000.00
Contingency added: $1,700.00
Left over, or still to find: $1,300.00
Average cost per room: $3,740.00

The priced work comes to $17,000 and the 10% contingency adds $1,700, so the budget is $18,700 against $20,000 set aside, leaving $1,300 spare and the whole budget covered. That is $3,740 for each of the five rooms, and labour is 35.3% of the priced work. Because no structural work is included, 10% is the right size of contingency here rather than the 20% an opened-up house would need.

Open this example in the calculator →

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Frequently asked questions

How much contingency should I add?

Ten per cent is normal for decoration, flooring and a new kitchen where nothing is opened up. Twenty per cent or more is realistic once walls, wiring, plumbing or the roof are involved, because the cost of what is found behind them is unknown until the work starts.

The contingency is not a fee and it is not meant to be spent. If it survives the job, it pays for the snagging list, for putting the rooms back together and for the first month of higher bills in a house that is suddenly bigger to heat.

Is the contingency worked out on the subtotal or on each item?

On the subtotal. Every stage you enter is added up first, then the contingency percentage is applied to that total and added on top. A 15% contingency on a $37,700 subtotal is $5,655, and the realistic budget is $43,355.

That matters when you change one line: adding $1,000 of materials raises the contingency too, because a bigger job contains more unknowns. The percentage is applied once rather than to each item separately, so the order of the lines makes no difference to the total.

What is missing from the renovation budget?

Sales tax or VAT on materials and labour, any finance cost if you borrow for the work, and the value of your own time. Do it yourself labour is entered as zero here, so if you would otherwise pay a tradesperson, add what that would have cost. Professional fees belong in the permits and surveys line.

Living costs during the work are the easiest thing to forget: temporary accommodation, storage, eating out while the kitchen is unusable, and the cost of moving furniture twice. The other costs line exists for exactly those items.

What should I do when the budget is more than the money I have?

Read the difference and the share covered first: they tell you the size of the gap rather than the size of the project. The monthly saving figure spreads that gap across a year, which turns it into something you can act on rather than a number that stops the work.

The usual answers are to stage the work, to do the structural and hidden parts first while everything is open, and to postpone anything that can wait without causing damage. Decoration and furniture can follow later; wiring, drainage and damp cannot.