ProReckoner's farm calculators are built for Australian and US farmers, graziers and agronomists. Tools cover cropping and seeding (seeding rate, fertiliser rate, spray rate and chemical dilution), livestock management (weight gain, feed conversion ratio, stocking rate in DSE), water and land (rainfall volume, dam capacity, paddock area) and farm business (grain storage, break-even yield, fuel cost). All tools support both metric (ha, kg, mm, L) and imperial (ac, lb, inches, gallons) units — switch with the Metric/Imperial toggle at the top.
Cropping & Seeding
3 toolsSeeding Rate Calculator
kg/ha seed required from target plant population, thousand grain weight (TGW), germination and establishment rates. Calculates total seed and bags needed.
Seed rate (kg/ha) = (Plants/m² × TGW g) ÷ (Germination% × Establishment% × 1000)
Target populations (plants/m²): Wheat 150–200 · Barley 130–180 · Canola 40–60 · Lupins 40–70 · Chickpeas 30–45TGW varies year to year — always use current season's seed test. A 5g difference in TGW changes seed rate by ~15%.
Fertiliser Rate Calculator
Total fertiliser and nutrient applied from application rate and paddock area. Includes cost estimate and nutrient content calculator.
Urea: 46% N · DAP: 18% N, 20% P · MAP: 11% N, 21.9% P · Muriate of Potash: 50% K · Gypsum: 16% S
Single Super: 8.8% P, 11% S · Ammonium Sulphate: 21% N, 24% S
Spray Rate / Chemical Dilution
Two modes — how much chemical to add per tank, or how many hectares a tank will cover. Supports L/ha and imperial units.
Chemical per tank = Rate (L/ha) × Area covered (ha)
Area per tank = Tank size (L) ÷ Carrier volume (L/ha)
Mixing order: Fill tank to 50% with water → add chemical → top up with water → agitate.Always read the label. Wear PPE. Check withholding periods and re-entry intervals.
Livestock
3 toolsLivestock Weight Gain (ADG)
Average daily gain from start weight, end weight and days on feed. Benchmarks against species targets. Includes sale value estimate.
ADG = (End weight − Start weight) ÷ Days
Target ADG benchmarks:Cattle (feedlot): ≥1.2 kg/day · Cattle (grass): 0.5–1.0 kg/day
Lamb (prime): ≥0.30 kg/day · Sheep: ≥0.25 kg/day · Pig: ≥0.85 kg/day
Feed Conversion Ratio (FCR)
Feed efficiency from total feed consumed and weight gained. Benchmarks against species targets with cost per kg of gain.
FCR = Feed consumed (kg) ÷ Weight gained (kg)
Lower FCR = more efficient. Industry benchmarks:Feedlot cattle: 6–8 · Grass-fed cattle: 12–18 · Sheep: 6–9 · Lamb: 5–8 · Pig: 2.5–3.5 · Broiler: 1.8–2.2
Improving FCR: optimise ration energy density, control feed wastage, manage parasite burden, ensure ad-lib water.
Stocking Rate (DSE/ha)
Stocking rate in Dry Sheep Equivalents per hectare for Australian grazing properties. Converts all livestock classes to a common DSE unit.
Total DSE = Number of animals × DSE per animal
Typical carrying capacity (DSE/ha): High-rainfall pasture: 10–25 · Tablelands: 5–15 · Wheat-sheep zone: 3–8 · Semi-arid: 0.5–3
Water & Land
3 toolsRainfall / Irrigation Volume
Total water volume from a rainfall event or irrigation application over any paddock area. Returns kL, ML and acre-feet.
Volume (kL) = Area (ha) × Rainfall (mm) × 10
Rule of thumb: 1mm of rain over 1 hectare = 10,000 litres (10 kL)Examples: 25mm on 100ha = 25,000 kL (25 ML) · 1" on 247ac ≈ same volume
For dam/catchment runoff, multiply by a runoff coefficient (typically 0.3–0.8 depending on slope and soil).
Dam Capacity Calculator
Estimated water storage capacity of a farm dam from surface dimensions and depth. Returns kL, ML and livestock water days.
Volume (m³) = L × W × D × Shape factor
Shape factors: Rectangular 0.6 · Circular 0.6 · Irregular 0.5 (accounts for sloping sides)Stock water requirements (L/day): Cattle 50L · Sheep 5L · Horses 45L
Allow 30% reduction from nominal capacity for sediment accumulation and evaporation.
Paddock Area Calculator
Paddock area in hectares and acres from dimensions. Supports rectangular, triangular and circular paddocks. Includes perimeter and fencing estimate.
1 hectare = 10,000 m² = 2.471 acres
Rectangle: L × W · Triangle: Heron's formula · Circle: π × r²
Common paddock conversions: 1 km × 1 km = 100 ha · 1 mile × 1 mile = 640 acres (1 section)For irregular paddocks, divide into rectangles and triangles and add the results.
Farm Business
3 toolsGrain Storage Volume
Estimated grain storage capacity in tonnes and bushels from silo, bunker or shed dimensions. Adjusts for grain density and moisture content.
Silo volume = π × r² × height
Tonnes = Volume (m³) × Grain density (t/m³)
Grain densities (t/m³): Wheat 0.78 · Barley 0.62 · Canola 0.67 · Sorghum/Corn 0.72 · Oats 0.50Allow 5–10% headspace for aeration. Check moisture before sealing storage — high moisture causes spoilage.
Break-Even Yield Calculator
Minimum yield needed to cover all costs at a given grain price. Enter fixed costs, variable costs per hectare and expected grain price to find your break-even point.
Break-even yield = Total costs ÷ (Price/t × Area)
Reducing break-even yield: Shop for cheaper inputs · Increase grain price through marketing · Reduce variable costs through precision agriculture · Share machinery costs.
Farm Fuel Cost Estimator
Total fuel cost and cost per hectare for farm operations. Pre-loaded with typical fuel consumption rates by operation type.
Deep ploughing: 20–30 · Cultivation: 12–20 · Seeding: 6–12 · Spraying: 2–5
Harvesting: 15–25 · Hay baling: 8–15 · Fertiliser spreading: 4–8
Actual consumption varies with soil type, tractor size, implement and speed.