How this calculator works
There are two ways to price an epoxy floor, and each needs different numbers, so the calculator has a DIY kit mode and a professional install mode.
DIY is sold in kits, and a kit’s label tells you the area it covers in one coat (for example “covers 36 m²”) and its price. So you only need the floor area, the number of coats, and those two label figures:
floor area = length × width (add sections for an L-shape)
coated area = floor area × coats
kits = round up (coated area × (1 + waste %) ÷ kit coverage)
DIY cost = kits × price per kit
Professional install is simpler still: an installer gives a single rate per unit area that already bundles preparation, materials, coats and finish, so the cost is just:
installed cost = floor area × price per square foot (or m²)
That is why coats, kit coverage and flake only appear in DIY mode - in a pro quote they are already baked into the rate. Decorative flake is broadcast over the floor once, not per coat, so it scales with the floor area, not the coated area. Everything runs in exact metric internally, so switching units never changes the answer - only the displayed numbers do.
Worked example
This example follows the unit system you pick in the calculator above.
A 6 × 6 m double garage (36 m²), two coats, kits that each cover 24 m², +10% waste:
- Floor area: 6 × 6 = 36 m².
- Coated area: 36 × 2 coats = 72 m².
- With 10% waste: 72 × 1.1 = 79.2 m² to cover.
- Kits: 79.2 ÷ 24 = 3.3, so buy 4 kits. At $150 each that is $600 DIY.
- Or a pro at 80 / m²: 36 × 80 = 2,880 installed.
Typical garage sizes and cost
Garage floors fall into a few standard sizes. This table gives the rough footprint and an indicative professionally installed cost band (solid colour at the low end, flake and metallic higher) - use it as a sanity check, then enter your own measurements and price above:
| Garage | Typical size | Floor area | Indicative installed cost (2026) |
|---|
| Single car | 3.6 × 6 m | ~22 m² | $700 - $2,900 |
| Two car | 6 × 6 m | ~36 m² | $1,200 - $4,800 |
| Three car | 9 × 6.7 m | ~60 m² | $2,000 - $7,900 |
Cost bands are a rough guide that move with the market and the system you choose; preparation can be 30-50% of a professional quote on a slab that needs grinding or crack repair. For the full breakdown, see how much it costs to epoxy a garage floor and whether it is worth it.
What it costs and how it is sold where you are
In New Zealand, the coating is usually called an epoxy or resin floor coating, sold by the litre, with resin and hardener supplied as a two-part kit. Get a couple of local quotes for a price, and price DIY kits by the litre you need - the calculator above works out both the litres and the kits.
The three common garage finishes use the same area × coats ÷ coverage math, just with different products and an extra step for the decorative ones:
- Solid colour - a coloured base coat and a clear topcoat. The cheapest option and the easiest to do yourself. Leave the flake setting on “no flake”.
- Flake (chip) - colour chips broadcast into a wet base coat, then locked in under one or two clear topcoats. Hides imperfections and adds grip. Pick a light scatter or a full broadcast in the calculator to add the flake weight.
- Metallic - a tinted metallic pigment troweled and rolled for a marbled look, under a clear topcoat. The most expensive and the hardest to get right, usually left to a pro.
Why prep is half the job
Epoxy is only as good as its bond to the concrete, so the preparation matters more than the coating - the full routine is in how to prep a garage floor for epoxy:
- Clean and degrease the slab - oil and tyre marks will stop epoxy sticking.
- Profile the surface by diamond grinding or acid-etching so the coating keys into the concrete rather than sitting on a sealed surface.
- Check for moisture - a slab that wicks water will push the coating off. Tape a plastic sheet down overnight and look for condensation before you start.
- Fill cracks and joints and let everything fully dry before the first coat.
- Mind the pot life - mixed epoxy starts curing in the bucket, so cut in and roll a coat before it thickens, and mix only what you can lay.
Tips for ordering
- Measure the floor, not the garage’s outside dimensions, and add a section for any L-shape or extra bay rather than averaging.
- Round up to whole kits - the calculator does this - and keep a little spare for touch-ups, since a later batch may not match.
- Match the coverage figure to your actual product and surface; bare or porous concrete covers less than the tin’s best-case number.
- This tool sizes the epoxy, kits and a cost estimate, not the floor’s structural condition - have a pro look at a slab with heavy cracking or moisture problems first.
For the step-by-step, see how to epoxy a garage floor and how much epoxy you need; for the finished floor, how long it lasts and how to clean it.
