Home Decor Tools & Calculators
Free, practical calculators to plan your decorating project before you buy anything. Every calculator runs in your browser, your numbers are never sent to us, and each tool links to a full guide that explains the numbers.
These tools are a supplement to the guides on this site, not a replacement for them. Use a calculator to work out the numbers, then read the linked guide to understand what the numbers mean and how to use them in your room.
Paint Calculator: How Much Paint You Need
Free paint calculator: work out how many gallons or litres of paint you need for a room, including doors, windows and coats. Includes doors, windows and coats.
Rug Size Calculator: Find the Right Rug for Your Room
Free rug size calculator: find the right rug size for your living room, bedroom or dining room, based on your sofa, bed or table size.
Room Size Calculator: Area, Perimeter & Square Footage
Free room size calculator: work out a room's area in square feet and square metres, and its perimeter, from the length and width.
Flooring Calculator: How Much Flooring Do I Need?
Free flooring calculator: work out how much hardwood, laminate, vinyl, tile or carpet you need, including a waste allowance, for any room size.
Wallpaper Calculator: How Many Rolls Do I Need?
Free wallpaper calculator: work out how many rolls of wallpaper you need for a wall or a room, including pattern repeat — buy the right number of rolls.
Curtain Calculator: Width, Length & Fullness
Free curtain calculator: work out the curtain width, length and fullness you need for a window, based on the rod and the drop, for any window size.
Tile Calculator: How Many Tiles Do I Need?
Free tile calculator: work out how many tiles you need for a floor or a wall, including a waste allowance for cuts, for floors and walls.
Lighting Calculator: How Many Lumens Do I Need?
Free lighting calculator: work out how many lumens and light fixtures you need for a room, based on its size and use, for living rooms and kitchens.
Bed Size Calculator: Compare Twin, Queen, King & More
Free bed size calculator: compare Twin, Twin XL, Full, Queen, King and California King dimensions in inches and centimetres — check the fit for your room.
Furniture Spacing Calculator: Gaps & Walkways
Free furniture spacing calculator: work out the recommended gaps between sofas, coffee tables, TVs and walkways for your room, in feet and inches.
Home Decor Budget Calculator: Plan Your Spending
Free home decor budget calculator: split your decorating budget across paint, furniture, textiles, lighting and decor, with a contingency.
How to use these tools
Enter the measurements for your room, in feet or inches as labelled, and press Calculate. The result shows the numbers you need, and the methodology section on each tool page explains the formula, so you can check it. If a result looks wrong, check the units: room sizes are in feet, furniture sizes are in inches, and paint coverage is in square feet per gallon.
All results are estimates based on standard formulas and general guidance. Check the result against the manufacturer's instructions before ordering materials, and keep a spare tin, box or roll for repairs.