Free online calculators for the trades that build and feed us
Fast, accurate tools for agriculture, mining, construction, livestock, electricity and water — with the formula, units and a worked example shown on every page.
Browse by category
Agriculture
3 toolsSpraying, seeding, fertiliser, water and paddock calculators for cropping and farming.
Mining
2 toolsGrade, blasting, haulage, stockpile and site planning calculators for mining operations.
Construction
2 toolsConcrete, earthworks, aggregate, drainage and setout calculators for builders and civil work.
Pastoral & Livestock
1 toolsStocking rate, feed, water and livestock planning calculators for graziers.
Water & Environment
2 toolsFlow, irrigation, pond sizing and environmental calculators for water management.
Electricity
4 toolsVoltage drop, cable sizing, solar output and energy cost calculators for electrical work.
Popular calculators
Spray Coverage Calculator
Work out how many hectares one full spray tank will cover at a given application rate.
ConstructionConcrete Volume Calculator
Calculate the cubic metres of concrete needed for a slab from its length, width and thickness.
ElectricityElectricity Cost Calculator
Calculate the running cost of an appliance or load from its wattage, daily hours and electricity rate.
MiningConical Stockpile Volume Calculator
Estimate the volume of a conical stockpile from its base diameter and angle of repose.
Pastoral & LivestockFeed Budget (Days of Feed) Calculator
Estimate how many days a paddock will feed a mob from pasture mass, area, stock numbers and intake.
ElectricitySolar Panel Output Calculator
Estimate daily and annual kWh output from a solar array given its size, peak sun hours and system losses.
Genuinely useful
Every calculator shows the real formula, the units, and a worked example — not just a number.
Fast & free
Static pages that load instantly and work on a phone in the field. No sign-up, no paywall.
Metric & imperial
Switch units with one tap where it matters. Built for both sides of the world.
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