Paint Calculator
Enter your room dimensions and get the exact number of litres of paint you need — accounts for doors, windows, and coats.
Open ToolHome Calculators
Accurate DIY calculators that take the guesswork out of home improvement — measure once, buy right.
Core Calculators
The full-size tools — enter any dimensions, any unit, any material.
Tile Calculator
Calculate how many tiles you need for any floor or wall area. Includes a 10% wastage buffer for cuts and breakages.
Open ToolTile Cost Calculator
Estimate the total cost of tiles, adhesive, grout and labour for any floor, bathroom or wall tiling project.
Open ToolConcrete Volume Calculator
Estimate the m³ of concrete needed for slabs, footings, or columns — with a 5% overage recommendation.
Open ToolGravel Calculator
Estimate gravel volume, weight in tons, and bag count for pathways, drainage, and driveway projects.
Open ToolTile Calculators by Room Size
Already know your room's dimensions? Skip straight to a pre-filled calculator with sizing advice specific to that footprint.
40 sq ft
5×8 Bathroom
Working around the toilet, vanity and shower pan in a small bathroom footprint.
Open Calculator →80 sq ft
8×10 Room
Master bathrooms, double vanities, and laundry or utility room layouts.
Open Calculator →100 sq ft
10×10 Room
Tile size and grout choices that make a small bedroom or kitchen feel bigger.
Open Calculator →120 sq ft
10×12 Room
Balanced layouts for a standard bedroom, including closets and doorway transitions.
Open Calculator →144 sq ft
12×12 Room
Centerline layouts and equal cuts for a perfectly square footprint.
Open Calculator →180 sq ft
12×15 Room
Choosing which way tile should run in a rectangular living or dining room.
Open Calculator →225 sq ft
15×15 Room
Expansion joints, drainage and slab prep for a large room or outdoor patio.
Open Calculator →400 sq ft
20×20 Room
Ordering by the pallet, dye-lot matching, and phased installs for very large floors.
Open Calculator →Free Home Improvement Calculators — Plan Your Project with Confidence
Home improvement projects — whether you're repainting a bedroom, retiling a bathroom, laying a gravel path, or pouring a concrete slab — always involve materials estimation. Ordering too little means costly return trips to the hardware store; ordering too much wastes money. The calculators on this page give accurate material estimates in seconds, so you can plan and budget a project with confidence before buying a single tin or bag.
Paint Calculator — Exactly How Many Litres You Need
One of the most common mistakes in DIY painting is buying the wrong amount of paint. Our online paint calculator takes the length, width, and ceiling height of your room, accounts for windows and doors, and calculates the exact number of litres required for one or two coats. It factors in the standard paint coverage rate (approximately 10–12 m² per litre for emulsion) and works for anything from a single feature wall to a whole house.
Tile Calculator — Never Run Short (or Overbuy)
Our tile quantity calculator takes the dimensions of any floor or wall and your chosen tile size, and instantly returns how many tiles you'll need, including a 10% wastage buffer for cuts, breakages, and future repairs. If your room matches one of the common sizes above, the pre-filled room calculators add sizing and layout advice specific to that footprint on top of the same math.
Tile Cost Calculator — Budget Your Tiling Project
Once you know your tile count, use the tile cost calculator to estimate the full project spend — tile material, adhesive, grout, and optional labour cost — broken down line by line in your currency of choice.
Concrete Volume Calculator — Slabs, Footings & Columns
Concrete is sold by the cubic metre (m³) or cubic yard, so knowing your volume accurately matters before hiring a transit mixer or ordering ready-mix. The concrete calculator covers rectangular slabs, circular slabs, and rectangular footings, with a 5% recommended overage for spillage and uneven ground.
Gravel Calculator — Pathways, Driveways & Drainage Beds
The gravel calculator converts length, width, and depth into cubic metres, cubic feet, kilograms, tons, and bag count, with a wastage buffer for compaction and uneven surfaces — useful for landscaping beds, driveway topping, French drains, and backfill.
For more tools, explore the finance calculators (including a home loan EMI calculator), or browse all free tools on civvy.tech.