Agriculture calculators
Field arithmetic for growers and agronomists. Recommended application rates vary by crop, soil and region, so you enter them; the calculator does the conversion.
Aquaculture
- Fish Pond Stocking Density CalculatorWork out how many fingerlings to stock in a pond from its area and depth, your target yield, harvest weight and expected survival, with fish per m² and per m³.
- Aquaculture Dissolved Oxygen Demand CalculatorEstimate how much oxygen a fish stock consumes from its biomass and consumption rate, the water flow that would supply it, and the aerators needed.
Crops & planting
- Crop Rotation Area CalculatorSplit your cropping land into equal rotation courses: net area after headlands and tracks, area per crop each year, and a field-by-year rotation plan.
- Plant Nursery Tray Requirement CalculatorFind how many plug trays, cells and seeds to sow for a transplant order, allowing for germination and establishment losses and spare plants.
- Orchard Tree Count CalculatorCount the trees an orchard block holds from its area and spacing, for square or rectangular, triangular (hexagonal) and quincunx layouts.
Farm business
- Farm Labor Cost CalculatorAdd up the cost of a farm crew from workers, hours, days and the hourly wage, plus employer on-costs and other costs, with cost per hour and per hectare or acre.
- Agricultural Loan Break Even CalculatorSee the crop price and yield you need to cover operating costs plus loan repayments per hectare or acre, and the margin left at your expected yield and price.
- Farm Equipment Depreciation CalculatorDepreciate a tractor or farm machine by straight line, declining balance or sum-of-years’ digits, with each year’s charge, book value and a full schedule.
Farm infrastructure
Fertiliser & soil
- Fertiliser NPK CalculatorTurn an N:P₂O₅:K₂O dose into kilograms of nitrogen, phosphate and potash fertiliser (such as urea, DAP and MOP), allowing for the N in DAP.
- Fertiliser Application Rate CalculatorConvert a nutrient rate (kg/ha or lb/acre) into the amount of fertiliser product per hectare, per acre and for the whole field, with bag count.
- Compost Volume CalculatorWork out how much compost or mulch you need to cover an area to a given depth, in m³, cubic yards, litres, tonnes and bags.
- Manure Application Rate CalculatorFind the manure or slurry rate that supplies a nutrient target, from the manure’s nutrient content and first-year availability, in t/ha, tons/acre or gal/acre.
- Lime Application CalculatorConvert a soil-test lime requirement into the amount of your liming product, adjusting for its neutralising value (ECCE/CCE) and your tillage depth.
- Soil Carbon Stock CalculatorEstimate the organic carbon stored in a soil layer from carbon %, bulk density, depth and stone content, in tonnes C and CO₂e per hectare and field.
Greenhouse
- Greenhouse Ventilation CalculatorSize greenhouse exhaust fans from the house volume and the air changes per hour you want, in m³/h and CFM, and count how many fans you need.
- Greenhouse Heating Load CalculatorEstimate the heater size a greenhouse needs from its covering area, U-value, the inside–outside temperature difference and air leakage.
Greenhouse & hydroponics
- Hydroponic Nutrient Concentration CalculatorFind the grams of fertiliser to dissolve for a target ppm of nitrogen, phosphorus, potassium or another nutrient, with P₂O₅ and K₂O label conversion.
- Aquaponics Water Flow CalculatorSize the pump flow for an aquaponics system from the fish tank volume and the turnovers per hour you want, in litres per hour, US gph and gpm.
Irrigation
- Drip Irrigation Discharge CalculatorWork out the number of drippers, total system discharge, the application rate in mm per hour and how long to run a drip system to apply a given depth.
- Irrigation Scheduling CalculatorEstimate how often to irrigate and how much water to apply from ET₀, crop coefficient, soil water holding and root depth, using the FAO-56 method.
- Soil Water Deficit CalculatorFind how many millimetres of water the root zone needs to return to field capacity from a soil moisture reading, and how depleted it is.
Livestock
- Livestock Feed Ration CalculatorMix two feeds to hit a target crude protein (or other nutrient) level with the Pearson square, and get the percentage and weight of each feed in the batch.
- Cattle Milk Yield CalculatorTurn a herd’s daily milk into yield per cow in milk and per cow in the herd, 4% fat-corrected milk (Gaines) and a 305-day figure at today’s rate.
Machinery
Poultry
- Poultry Feed Conversion CalculatorCalculate a broiler flock’s feed conversion ratio, FCR on weight gain, livability and European Production Efficiency Factor from feed, birds and weights.
- Poultry Mortality CalculatorWork out cumulative flock mortality, livability, birds remaining and the average daily and weekly mortality rate from birds placed, deaths and culls.
Seed & planting
- Seed Rate CalculatorWork out how much seed to buy for a field, either from a recommended seed rate or from target plant population, seed weight and germination.
- Plant Population CalculatorCount plants per acre, per hectare and per square metre from row spacing and in-row plant spacing, and the total for your field.
- Plant Spacing CalculatorFind the plant-to-plant spacing that gives a target population per hectare, acre or m², for fixed rows, square or triangular planting.
Spraying
- Pesticide Dilution CalculatorWork out how much pesticide to add to a knapsack or tank from the label dose per litre, or from the active-ingredient strength you want (C1V1 = C2V2).
- Sprayer Tank Mix CalculatorFrom spray volume per acre or hectare, tank size and product rate, find how much product goes in each tank, how many loads and the final part-tank.
Storage
- Fodder Storage Capacity CalculatorWork out the tonnes of silage or hay a clamp, bunker or barn holds from its size and the fodder’s bulk density, and how many days it will feed your animals.
- Grain Storage Volume CalculatorWork out how much grain a round bin holds from its diameter, level grain depth and peak height, in cubic metres, US bushels and tonnes at your bulk density.
Water & irrigation
- Rainfall Harvest Volume CalculatorWork out how much rainwater a roof or catchment can collect from its area, the rainfall and a runoff coefficient, in litres, cubic metres and US gallons.
- Farm Pond Volume CalculatorFind the water a dug farm pond holds from its top length and width, depth and side slope, in cubic metres, litres, cubic feet and US gallons.
- Irrigation Pump Power CalculatorWork out the water power, pump shaft power and electrical input of an irrigation pump from flow rate, total head and efficiencies, in kW and horsepower.
Yield & farm economics
- Crop Yield per Acre CalculatorTurn a harvested weight and field area into yield per acre and per hectare in kg, quintals, pounds, bushels and tonnes, with optional moisture adjustment.
- Harvest Revenue CalculatorEstimate crop sales income from yield per acre or hectare, area, price, post-harvest losses, selling costs and other income such as straw.
- Farm Gross Margin CalculatorCalculate a crop enterprise’s gross margin: output value minus variable costs (seed, fertiliser, sprays, fuel, labour), per acre, per hectare and in total.