Hobby

Most used

• Suit Size CalculatorTurn your chest measurement into a European and US suit jacket size, rounded to the nearest two-centimetre step.

All, A–Z

• Acres Per Hour CalculatorWork out mowing and field-work productivity in acres per hour from cutting width, ground speed, and field efficiency.
• Air Conditioner BTU CalculatorThe cooling capacity a room needs in BTU per hour, from its floor area in square feet at 20 BTU per square foot.
• Asphalt CalculatorHow many tonnes of hot-mix asphalt an area needs, from its size, the compacted layer thickness and the density of the mix.
• Beaufort Scale CalculatorAny wind speed in km/h as a Beaufort force from 0 to 12, using the WMO bands in metres per second.
• Blue Hour CalculatorFind when the blue hour starts and ends at any coordinates — the sun between 4° and 6° below the horizon, morning and evening, on any date.
• Board Foot CalculatorBoard feet of lumber from thickness and width in inches and length in feet — the mill's own measure.
• Ceiling Fan Size CalculatorFind the blade span that suits your room, from its length and width — the middle of the recommended band for that floor area.
• Concrete Block CalculatorHow many concrete blocks a wall needs, plus the mortar, from the published blocks-per-square-foot figure and a waste allowance.
• Concrete CalculatorEstimate slabs, rectangular footings and round columns from US or metric dimensions; see cubic yards, cubic metres and whole bags.
• Cubic Feet CalculatorCubic feet from length, width and height measured in feet, inches, centimetres, metres or yards. Cubic yards and cubic metres shown alongside.
• Cubic Yard CalculatorCubic yards of topsoil, mulch, gravel or concrete from an area in feet and a depth in inches — the way bulk material is actually ordered.
• Drywall CalculatorHow many drywall sheets a wall and ceiling area needs, plus the joint compound and tape that go with it, from a maker's coverage table.
• Fence Post CalculatorHow many posts a straight fence run needs, from its total length and the spacing between the posts.
• Flooring CalculatorHow many boxes of flooring a room needs, from its length and width, the coverage per box and a waste allowance.
• Golden Hour CalculatorFind when the golden hour starts and ends at any coordinates — the sun between 6° above and 4° below the horizon, on any date.
• Grass Seed CalculatorHow much grass seed a lawn needs, from its area in square metres and the sowing rate in grams per square metre.
• Gravel CalculatorEstimate gravel from a measured area or length, width and depth. See cubic yards, cubic metres, US short tons and metric tonnes together.
• Heat Pump Size CalculatorThe heat output a heat pump has to deliver, from heated area, insulation standard and household size.
• Mulch CalculatorHow many 2 cubic foot bags of mulch a bed needs, from its area in square feet and the depth in inches.
• Paint CalculatorHow many litres of paint a job needs, from the wall area, the number of coats and the coverage per litre.
• Pool Pump Size CalculatorWork out the flow rate a pool pump needs from the pool's dimensions and your turnover time.
• Pool Volume CalculatorHow many gallons your pool holds, for rectangular, round and oval shapes, with separate shallow and deep end depths. Litres shown alongside.
• Rainwater Harvesting CalculatorLitres you can collect from a roof, from its plan area in square metres, the rainfall in millimetres and a runoff coefficient.
• Ramp Length CalculatorThe sloped length of a wheelchair ramp from the rise it climbs and the slope ratio — 12 for the ADA 1:12 maximum.
• Roof Pitch CalculatorThe roof pitch angle in degrees from the rise and the run. A 6:12 roof is 26.57°, the same slope as a grade of 50 %.
• Roof Square Footage CalculatorCalculate sloped roof area from its horizontal footprint and pitch. Use square feet or square metres, with worked examples and no hidden waste allowance.
• Rug Size CalculatorThe largest standard rug that fits your room and still leaves an even strip of bare floor on every side.
• Sand CalculatorHow many tonnes of sand an area needs, from its size, the depth of the layer and the bulk density of the sand.
• Ski Size CalculatorA starting ski length from your height, ability and terrain — a shop guideline, not a measurement.
• Stair CalculatorHow many steps a flight needs, from the total floor-to-floor rise and the riser height you are aiming for.
• Surfboard Volume CalculatorLitres of board for your weight, ability and paddle fitness — a shaper's guideline, not a specification.
• Tile CalculatorHow many tiles a floor needs, from its area, the size of one tile and an allowance for cuts and breakages.
• Topsoil CalculatorHow much topsoil an area needs, from its size, the depth of the layer and the bulk density of the soil.
• Wallpaper CalculatorHow many rolls of wallpaper a wall needs, from its area, the size of one roll and a waste allowance.
• Wheel Offset CalculatorCompare wheel width, ET and spacers. See outer movement, inner clearance, track and effective offsets together; add measured widths for backspacing.