Sprayer Calibration Calculator
Measure once, know your real litres per hectare — then put the label rate on target.
Calibration is the step between a recommendation and a correct application. Most off-target dosing in banana blocks is not a maths error at the mixing bench — it is a sprayer that was never measured. This tool turns a five-minute water test into the numbers you need.
Sprayer calibration calculator
Pick a method, enter your water-test measurements, and compare the real output with your target.
The formulas#
Nozzle/boom rate (L/ha) = 600 × output per nozzle (L/min)
÷ speed (km/h) ÷ spacing or band width (m)
Per-plant rate (L/ha) = water collected (L) ÷ plants sprayed
× plants per hectare
Fixed-run rate (L/ha) = water used (L) × 10,000
÷ run length (m) ÷ swath width (m)
Deviation (%) = (actual − target) ÷ target × 100
Hectares per tank = tank volume (L) ÷ actual rate (L/ha)
Plants per tank = hectares per tank × plants per hectare
Product per tank = tank volume ÷ 100 × product per 100 L
Water for the block = block area (ha) × actual rate (L/ha) ÷ 1,000The constant 600 comes from the area one nozzle covers per minute: at V km/h and swath S metres that is V × S ÷ 600 hectares, so litres per hectare is Q ÷ (V × S ÷ 600).
Worked examples#
Nozzle/boom — one nozzle puts out 1.5 L/min, spacing 2.0 m, you walk 4.0 km/h:
Rate = 600 × 1.5 ÷ 4.0 ÷ 2.0 = 112.5 L/haAgainst a 100 L/ha target that is +12.5% — a little fast. At 4.5 km/h the same rig delivers exactly 100 L/ha.
Knapsack per plant — 1.6 L sprayed over 20 plants, stand is 1,667 plants/ha:
Per plant = 1.6 ÷ 20 = 0.08 L
Rate = 0.08 × 1,667 = 133.4 L/haFixed run — 0.6 L used over a 20 m run wetting a 1.0 m swath:
Rate = 0.6 × 10,000 ÷ 20 ÷ 1.0 = 300 L/haChoosing a method#
| Method | Use it when | Watch out for |
|---|---|---|
| Nozzle/boom | Rigid boom, tractor or ATU-mounted, or a single nozzle on a cart | Speed must match real spraying, not marching pace; pressure changes output |
| Per-plant knapsack | Directed sprays at the mat, suckers or bunch | Plants must be typical — measure a full row, not the easy ones |
| Fixed run | Band spraying along the row with a knapsack or trolley | Swath width must be the wetted width, not the nozzle fan rating |
Reading the results#
| Output | Why it matters |
|---|---|
| Actual rate | The real L/ha your rig applies — this is what the label is written against |
| Deviation | Within ±10% is good calibration; beyond ±25% re-check nozzle and pressure |
| Hectares per tank | How far one tank goes — plan refills before you leave the shed |
| Product per tank | Mix once, correctly: dose the tank you actually have |
| L per plant | Sanity-check against directed-spray volumes of roughly 1–3 L/plant |
| Water for the block | Lets you pre-mix the day's total instead of guessing |
Next steps#
- Put the volume in context: spray-volume guidance sits with Integrated pest management and Banana pests.
- Know what you are targeting: Diseases and Crop care.
- Log every application: Record-keeping templates.