Home & DIY calculators
Measure twice, calculate once, buy slightly more paint than that.
Paint and flooring, bricks, roofs and stairs, fences and decks, energy and solar, and kitchen maths.
Decorating and floors
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Paint Calculator
How much paint you need for a room, minus doors and windows. e.g. Paint needed (litres) = 7.4 -
Flooring and Tile Calculator
How much flooring or how many tiles, including waste. e.g. Flooring to buy (m²) = 15.4 -
Wallpaper Calculator
How many rolls of wallpaper a room takes, counted strip by strip. e.g. Rolls to buy = 9 rolls -
Area Calculator
Area of a rectangle, circle or triangle, in any unit. e.g. Area = 20 m² -
Room Volume Calculator
The volume of a room or box, in cubic metres, feet and litres. e.g. Volume = 50 m³ -
Moving Box Calculator
How many moving boxes to get, by size, and the tape to go with them. e.g. Boxes in total = 66 -
Moving Cost Calculator
What a move will cost: the truck, the movers, the boxes and a buffer for surprises. e.g. Cost of the move = 1,496.00
Building and renovating
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Concrete Calculator
How much concrete for a slab, path or round post hole. e.g. Concrete needed = 1.32 m³ -
Drywall Calculator (Plasterboard)
How many sheets of drywall or plasterboard for a room, with screws. e.g. Sheets = 17 -
Brick and Block Calculator
How many bricks or blocks for a wall, with openings taken out and waste added. e.g. Bricks or blocks = 672 -
Roofing Calculator
The area of a roof from its footprint and pitch, in squares and bundles of shingles. e.g. Roof area = 120.7 m² -
Stair Calculator
Number of steps, riser height, total run and stringer length for a staircase. e.g. Risers (steps up) = 15 -
Board Foot Calculator
How many board feet of lumber you need, and what it costs at the yard’s price. e.g. Board feet = 80
Garden and outdoors
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Fence Calculator
Posts, panels, rails and pickets for a fence of any length. e.g. Posts = 18 -
Deck Calculator
Deck boards, joists and screws for a deck of any size. e.g. Deck boards = 27 -
Pool Volume Calculator
How much water a pool, pond or hot tub holds, how long it takes to fill and what it costs. e.g. Water = 48,000 L -
Mulch, Soil and Gravel Calculator
How many cubic yards, cubic metres or bags of mulch, soil, gravel or sand to buy. e.g. You need = 1.35 m³ -
Grass Seed and Sod Calculator
How much grass seed, or how many rolls of sod, your lawn needs. -
Plant Spacing Calculator
How many plants fit a bed at the spacing on the label, in rows or staggered. e.g. Plants = 67
Energy and running costs
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Electricity Cost Calculator
What an appliance costs to run per day, month and year. e.g. Cost per day = 1.50 -
EV Charging Cost and Time Calculator
How long an electric car takes to charge, and what it costs. e.g. Charging time = 5 h 24 min -
AC Size Calculator (BTU)
How many BTU an air conditioner needs for a room, adjusted for sun, people and kitchens. e.g. Cooling capacity = 8,000 BTU/h -
Solar Panel Payback Calculator
How many years solar panels take to pay for themselves, and what they save over 25. e.g. Pays for itself in = 10.6 years -
Fuel Cost Calculator
What a trip will cost in fuel, and how much each person pays. e.g. Fuel cost = 29.25 -
Fuel Economy Calculator (MPG and L/100 km)
Your car’s real fuel economy from the distance you drove and the fuel you used. e.g. Fuel economy = 7 L/100 km -
Heat Pump Savings Calculator
What a heat pump would save on heating each year, and how long it takes to pay back. e.g. Saving per year = 596.25
Kitchen
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Recipe Scaler
Scale a recipe up or down to any number of servings, ingredient by ingredient. e.g. Multiply everything by = 1.5 -
Party Food Calculator
How much food, drink and ice to get for a party, by the number of guests. e.g. Appetiser pieces = 120 -
Turkey Cooking Time Calculator
How long to roast a turkey, and how long to thaw it first. -
Baking Pan Size Converter
How much to scale a recipe for a different cake tin or baking pan. e.g. Multiply the ingredients by = 1.32 -
Coffee to Water Ratio Calculator
How much coffee to use for the amount of water, for any brewing method. e.g. Coffee = 31.3 g -
Recipe Cost per Serving Calculator
What a recipe costs to make, in total and per serving. e.g. Cost per serving = 3.00 -
Pizza Size Calculator: Which Is the Better Deal?
Which pizza order gives you more pizza for your money, one large or two smaller. e.g. Order A gives more pizza for the money, by = 18.5% -
Rice to Water Ratio Calculator
How much water your rice needs, how long it simmers and how much it makes. e.g. Water = 2 cups -
Baker’s Percentage Calculator
Grams of water, salt and starter for any flour or dough weight, at the hydration you want. e.g. Water = 350 g -
Dog Food Calculator
How many calories your dog needs a day, and how much of its food that is. e.g. Calories a day = 1,059 kcal
