Knapsack Load Planning & Mix the Right Tanks, Never Run Short

The tool works out the total spray volume by multiplying your area (converted to hectares) by the spray volume per hectare, then divides that by your tank capacity and rounds up to whole loads — because you cannot carry a fraction of a tank. For example, a 0.5 ha plot at 200 L/ha needs 100 litres of spray, which is seven loads from a 16-litre knapsack. It also shows the area each load covers so you can pace the field.

That comes from your product label and the target — many foliar sprays sit around 200–500 litres per hectare for a knapsack, lower for systemic products on small plants and higher for dense canopies that need full coverage. Use the label's recommended water volume for your crop stage; the tool then turns it into the total water and the number of loads. Getting this number right matters more than tank size for coverage.

Because a partial load still means another walk to the mixing point and another tank to fill — you cannot spray three-and-a-bit tanks, you spray four. Rounding up ensures the whole field is covered and tells you the real number of refills and the mixing batches to prepare. The area-per-load figure then spreads the field evenly across those whole loads so each tank does a fair share.

It is the total field area divided by the number of loads, giving an even split so you know roughly how far one tank should take you. Walking that area in mind helps you avoid the classic mistakes of dumping too much early and running dry, or spraying too thin and having product left over. Mark the field into that many strips and one tank should cover one strip at the right rate.

Enter your field in acres, hectares, guntha, bigha or square metres — the tool converts everything to hectares internally using exact factors (1 acre = 0.40468564 ha, 1 hectare = 10,000 m²). That means you can work in whatever unit your land is measured in and still get correct spray volume and loads. Regional units like guntha and bigha are supported because that is how many growers know their plots.

No — calibration sets the actual spray volume per hectare your walking speed and nozzle deliver, and this tool uses that figure to plan loads. Calibrate first by spraying a measured area with water and checking how much you use, then feed that true L/ha into the planner. Together they give you both the right rate and the right number of loads; this tool handles the planning side.

Divide your total product for the field by the number of loads to get the amount per tank, or use your label's per-litre dose times the tank capacity. The planner gives you the loads and the litres per load, which is the basis for splitting product evenly so every tank is mixed to the same strength. Even product per tank is what keeps the rate consistent across the field.

Yes — just enter the area you intend to spray rather than the whole plot, and the loads and volumes scale to it. This is handy for spot-treating a weedy corner, a disease hotspot or a headland, where mixing a full field's worth would waste product. Enter the real area to be treated and you mix only what you need.