Calculator Inputs
Example Data Table
| Product form | Method | Final volume | Rate / Setting | Product needed | Water to add |
|---|---|---|---|---|---|
| Liquid | Label rate | 10 L | 2 mL per L | 20 mL | ≈ 9.98 L |
| Liquid | Percent | 5 US gal | 0.5% | ≈ 94.6 mL | ≈ 18.83 L |
| Powder | Label rate | 15 L | 3 g per L | 45 g | ≈ 15 L |
| Liquid | Ratio | 20 L | 1 : 200 | ≈ 99.5 mL | ≈ 19.90 L |
Examples are for illustration only—your label values must override.
Formula Used
Active ingredient estimate: a.i.(g) = Product(g) × (a.i.% ÷ 100). Liquid a.i. uses density to convert mL to grams.
How to Use This Calculator
- Read the label and pick the same mixing method.
- Enter your final spray volume and select its unit.
- Fill in the method field: rate, percent, or ratio.
- Choose rounding to match your measuring tools.
- Press Calculate to see results above the form.
- Download CSV or PDF if you need a record.
Target spray volume sets the whole calculation
Enter the finished spray you need, not just the tank size. Typical garden batches are 1–5 L for hand sprayers and 10–20 L for backpacks. The calculator accepts liters, US gallons, and UK gallons, then standardizes units so the dose stays consistent.
Label-rate mixing converts “per liter” to total product
If the label says 2 mL/L and your target is 12 L, you need 24 mL. For dry products, 1.5 g/L at 8 L becomes 12 g. Use rounding to match your tools, such as 0.5 mL steps for syringes or 1 g steps for scales.
Percent solutions depend on formulation
A 0.5% liquid solution uses % ÷ 100 × Total(mL). For 5 US gal (≈ 18,927 mL), that is ≈ 94.6 mL of product, then top up with water. For powders, a practical garden approximation is 1% ≈ 10 g/L, so 0.5% ≈ 5 g/L.
Ratio mixes use parts to find the concentrate share
Ratios like 1:100 mean 1 part product in 101 total parts. The calculator applies Product = Total ÷ (ratio + 1). Example: 2 L at 1:200 gives ≈ 9.95 mL product. If a label states “mL per liter”, use label-rate instead of ratio.
Recordkeeping improves repeatability and compliance
Log crop stage, weather, nozzle type, and dilution so you can repeat good outcomes and avoid over-application. Notes entered in the calculator can be exported to CSV or PDF for your records.
| Date | Crop / Area | Method | Target Volume | Label Input | Product Needed |
|---|---|---|---|---|---|
| 2026-01-28 | Tomatoes (5 beds) | Label rate | 10 L | 2 mL/L | 20 mL |
| 2026-01-28 | Roses (border) | Percent | 5 US gal | 0.5% | ≈ 94.6 mL |
| 2026-01-28 | Herbs (pots) | Ratio | 2 L | 1:200 | ≈ 9.95 mL |
| 2026-01-28 | Lawn edge | Label rate | 8 L | 1.5 g/L | 12 g |
FAQs
Which mixing method should I choose?
Match the product label. Use label rate for mL/L or g/L, percent for solutions written as %, and ratio for mixes written like 1:100. If unsure, follow the label and local guidance.
Does the calculator account for product density?
It assumes liquid concentrates measure by volume (mL) and powders by weight (g). Density varies by formulation, so for strict accuracy on liquids by mass, use label guidance or a manufacturer density value.
Why does powder percent use an approximation?
Garden mixing often treats 1% w/v as about 10 g per liter. It is practical for many wettable powders, but labels may specify a different approach. Prefer the label if it conflicts.
How do I measure small volumes accurately?
Use an oral syringe or graduated cylinder for 1–20 mL. For very small amounts, mix a larger batch, or create a measured stock dilution first, then dose from that stock to reduce error.
Can I mix in gallons and still get correct results?
Yes. Enter your volume in US or UK gallons and the calculator converts internally. Always keep your measuring tools consistent, and avoid mixing US and UK gallon assumptions in the same job.
What rounding should I use?
Choose the smallest increment your tools can reliably measure. For syringes, 0.5 mL or 0.1 mL works well. For powders, 1 g is common. Rounding too aggressively can shift concentration.
Is it safe to save and share the PDF/CSV report?
The report stores only your inputs and notes. Do not share it publicly if it contains sensitive location or crop details. Keep PPE and safety instructions from the label with your records.