A tank plan you can use beside the sprayer
You know the treated area and the spray volume your calibrated equipment applies there. The label tells you how much liquid product to use, but a full tank and the final short tank rarely need the same amount. This page turns those known quantities into a fill-by-fill plan.
Start with the label, not an estimated dose. The calculator does arithmetic for one liquid product measured in millilitres; it cannot decide whether the product, rate, timing or application method is suitable for your crop.
How to use it
Match the label wording
Choose mL product per area when the label gives a rate per hectare or acre. Choose mL product per 100 L water only when it explicitly says water. A rate per 100 L of finished spray is different and is outside this calculator.
Describe your actual spray job
Enter the area you will treat, your calibrated finished spray volume per area, and the usable volume you put in the tank. Tank size is a finished fill, not a guess at how much area it covers.
Read both tank amounts
Calculate the product for each full tank. If a partial tank remains, use its separate mix card for the final area. Compare the total product and finished spray with your plan before preparing anything.
Follow one spray job from field to tank
At 200 L/ha, it needs 460 L finished spray.
At 600 mL/ha, each gets 450 mL product.
Only 30 mL product for the final 0.05 ha.
The four fills use 1,380 mL product altogether. For each full tank, the simple volume estimate is 149.55 L water plus 450 mL product to reach 150 L finished spray. The final tank is about 9.97 L water plus 30 mL product to reach 10 L. Follow the label's mixing instructions and top up to the intended final mark.
Why the label's rate basis matters
A per-area rate follows the ground covered. First multiply treated area by calibrated spray volume per area to get total finished spray. Then work out how much area each tank covers and multiply that area by the label product rate.
Per-area label: product per tank (mL) = label mL/area × tank L ÷ calibrated L/area.
Total product (mL) = label mL/area × treated area. Approximate water (L) = finished spray L − product mL ÷ 1,000.
If the label instead says mL per 100 L water, the denominator is water. The calculator solves for water and product together so their estimated volumes reach the chosen finished fill. For example, a 100.1-L finished fill at 100 mL product per 100 L water contains 100 L water and 100 mL product under the additive-volume assumption.
Per-water label: water L = finished spray L ÷ (1 + label mL per 100 L water ÷ 100,000).
Product mL = water L × label rate ÷ 100. Real liquid volumes may not combine exactly, so use the tank graduation and label directions when filling.
The last tank deserves its own line
Suppose the spray plan calls for 250 L and your usable tank fill is 100 L. You need two full tanks and one 50-L tank, not three full tanks. At a label rate of 100 mL per 100 L water, each full tank contains about 99.9 mL product and 99.9 L water. The last tank contains about 49.95 mL product and 49.95 L water. Total product is about 249.75 mL.
A quick field check
If the final tank appears to need as much product as a full one, stop and check the remaining spray volume. If the plan divides exactly into full tanks, no partial tank should appear.
Check the plan before the first fill
A calculated tank amount is useful only when the label, field and sprayer describe the same job. Do this quick comparison before product goes into the tank:
Rate and restrictions
Confirm the product form, rate basis, crop and any spray-volume or concentration directions. This page cannot check those conditions for you.
Measured output
Use the output from the nozzle, pressure and travel speed planned for this pass. If calibration changes, recalculate the tank plan.
Treated area
Match the area to the actual rows or block being sprayed. The final partial tank should cover the remaining area, not another full tank's worth.
Before you mix
- Calibrate the sprayer. Output changes with nozzle, pressure, speed and setup. The entered L/ha or L/acre should be measured for this job.
- Use the label's actual wording. A per-area rate, a per-water rate, and a per-finished-spray rate are not interchangeable.
- Use the usable fill. If you leave headspace, enter the volume you actually prepare per full tank.
- Top up to the finished spray mark. The water result is approximate because volumes may not add perfectly. Follow the product label's mixing order and instructions.
- Keep the scope narrow. This page does not calculate dry products, multi-product mixtures, compatibility, personal protection, drift or application timing.
Frequently asked questions
Does this calculator recommend a spray rate?
What does mL per 100 L water mean here?
Can I enter a rate per 100 L of finished spray?
Why is the last tank different?
Is water an exact pour-in amount?
Can I use a dry product or several products?
What should I enter for spray volume?
What if calibration changes my spray volume?
Will switching hectares and acres change the mix?
Related farm tools
Use the Farm Land Area Calculator to check the area in this spray plan. The Crop Production Cost Calculator can then place the planned product purchase within your wider crop budget. Return here once the label rate and calibrated spray volume are known.