GreenThumb · Field Tool

Knapsack Calibration

Enter your measured values — results update as you type.

iJob details
1Walking speed

Walk 25 m out and back, twice. Enter each time in seconds.

Run 1 — Out25 m
secs
Run 1 — Back25 m
secs
Run 2 — Out25 m
secs
Run 2 — Back25 m
secs
Total 100 m in 76 s → speed4.74kph
2Spray width

Measure the swath width four times.

Trial 1
m
Trial 2
m
Trial 3
m
Trial 4
m
Average spray width1.20m
3Nozzle flow rate

Collect output for one minute, twice.

Trial 1
l/min
Trial 2
l/min
Average flow rate1.60l/min
4Product & tank
✓Product per knapsack
142 ml
of product per 20 l knapsack
Water volume applied169 l/ha
Knapsacks per hectare8.44
Product per knapsack0.142 l
Enter an ideal water volume to compare.
5Product needed for an area

Pick a product and enter the area in m² — get the total product to use.

—
of product for this area
Water needed for this area—
Water volume = (10,000 ÷ width ÷ 1,000) ÷ speed × 60 × flow rate.
Always check the product label on the container before mixing.