Household budget
Find out what is left each month, balance your spending with the 50/30/20 rule and trace your money flow from paychecks to savings.
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Home, utility & DIY calculators
Mortgages, rent vs buy, electricity, gas and water bills, heating, cooling load, and paint, wallpaper, flooring and concrete quantities.
Mortgage
Calculate monthly mortgage payments, loan-to-value (LTV) and total interest for equal (annuity) or declining instalments.
Open calculatorRent vs buy
Compare total cash spent on a mortgage and home ownership against renting and investing your down payment over a chosen horizon.
Open calculatorRental yield
Calculate annual gross and net rental yield from property purchase price, monthly rent, vacancy rate and running costs.
Open calculatorProperty sale tax
See whether the sale is exempt, the gain, the taxable part after a housing expense, the tax and the net amount.
Open calculatorHeat pump vs gas boiler
Estimate annual space-heating demand from floor area and insulation class, then compare heat-pump electricity cost (by SCOP) against a gas boiler.
Open calculatorAir-conditioning cooling load
Estimate required air-conditioner cooling capacity in watts and BTU/h from room floor area and thermal load per m².
Open calculatorHeating fuel comparison
Compare the annual cost of generating the same amount of useful heat across gas, pellets, coal, wood, heating oil, electric resistance and a heat pump.
Open calculatorDomestic hot water
Calculate thermal energy, electricity use and running cost to heat daily hot water by a chosen temperature rise.
Open calculatorHeat loss through a surface (U-value)
Calculate thermal energy lost (kWh) and heating cost through a wall, window or roof from its U-value, area and temperature difference.
Open calculatorGas bill
Convert gas meter readings from cubic metres (m³) into kilowatt-hours (kWh) and calculate your monthly bill including standing charges.
Open calculatorAppliance electricity cost
Calculate electricity consumption (kWh) and running cost for any appliance from its wattage and daily operating hours.
Open calculatorWater and sewage bill
Calculate your water and wastewater bill from meter consumption in cubic metres (m³) and local utility tariffs.
Open calculatorSeptic tank pump-out
Estimate daily wastewater inflow, how many days it takes to fill a holding tank, pump-outs per year and annual emptying cost.
Open calculatorRainwater tank
Work out how many litres of rain your roof collects, which tank size is enough and how much you save on water and sewage.
Open calculatorStandby power cost
Calculate the annual energy use (kWh) and cost of electronics left on standby 24/7.
Open calculatorLED bulb swap savings
Calculate the kilowatt-hours and money saved by replacing old bulbs with LEDs.
Open calculatorHeating degree days (HDD)
Estimate seasonal space-heating energy from heating degree days (HDD) and your building’s heat-loss coefficient (UA).
Open calculatorWall paint needed
Calculate how many litres of paint you need from wall area, number of coats and tin coverage (m²/L).
Open calculatorFlooring & tile packs
Calculate how many packs of laminate, wood flooring or tiles to buy from room area, cutting waste and pack coverage.
Open calculatorDew point
Calculate the Magnus dew-point temperature from air temperature and relative humidity.
Open calculatorWind chill
Calculate how cold the air feels on exposed skin from air temperature and wind speed.
Open calculatorWallpaper rolls needed
Calculate how many wallpaper rolls to buy from wall perimeter, room height, roll dimensions and pattern-matching waste.
Open calculatorConcrete slab volume
Calculate cubic metres (m³) of concrete needed for a rectangular slab or screed, including a waste margin.
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