Spray Mix Calculators Tank Mix Calculator

Tank Mix Calculator: Build Your Spray Tank Mix

Calculate the exact amount of each product per tank for a multi-product spray tank mix. Add up to 4 pesticide or fertilizer products, set your tank size and target GPA, and get oz per tank for each product in the correct WBAS mixing order — plus a printable mix sheet for your records.

⚠️ Always check each product label before tank mixing.

Not all products are compatible. Do a jar test with any new combination. This calculator computes amounts only — it does not assess chemical compatibility or legal registration.

On this page: Calculator · WBAS mixing order · Jar test guide · Tank mix tips · Related tools · FAQ

Mixing a single herbicide? Herbicide Mixing Calculator · Need the right nozzle for your rate? Spray Tip Calculator.

Calculator

Multi-Product Tank Mix Builder

Choose a mode: Tank Builder to calculate oz per tank for up to 4 products · Acres Planner to scale a mix across a full job · Volume Check to confirm your tank fill sequence adds up.

Enter your tank setup, then add each product. The calculator converts all rates to fl oz per tank and lists them in the correct WBAS mixing order.

Tank Setup

Products in Tank Mix

Enter each product below. Product type sets the WBAS mixing order automatically.

Product 1

Product 2

Product 3 (optional)

Product 4 (optional)

Need mixing order guidance? See the WBAS Mixing Order Guide for a full explanation of each step and why order matters.

Scale your tank mix across a whole job. Enter your tank size, GPA, total acres to treat, and up to 3 products to see total product needed, number of tanks, and amount per tank.

Job Setup

Products

Confirm your tank fill sequence. Enter your tank size and the volume of each product and water fill step to verify the total matches your tank capacity.

Products added (enter volume in fl oz)

Recommended tools for tank mixing

Accurate measurement and proper PPE are essential when building multi-product tank mixes:

See all recommended spray equipment including pressure gauges, nozzles, and measuring tools.

WBAS tank mix order: the correct sequence for every spray tank

The WBAS mixing order — Water, Buffer, Add products, Surfactant — is the industry-standard sequence for building a multi-product spray tank. Following it prevents incompatibility reactions, clogged nozzles, and uneven mixing. The Tank Builder tab assigns each product a position in this order automatically based on its product type.

StepWhat to AddProduct TypeWhy This Order
1Fill tank 40–60% full with clean water—Provides agitation medium; prevents concentrated product contact with tank walls
2Add buffering or compatibility agentsCompatibility agent / pH bufferAdjusts water pH before any actives; some products require pH 5–7 for stability
3Add WDG / DF — dry flowablesWDG, DF granulesDry formulations need time to fully disperse; add early with vigorous agitation
4Add WP — wettable powdersWP powderAlso need dispersion time; added after WDGs to allow each to wet out fully
5Add SC / FL — suspension concentratesSC, FL flowablePre-dispersed solids; add after dry formulations are well mixed
6Add EC — emulsifiable concentratesEC concentrateOil-based; added after water-based products are in solution
7Add SL — soluble liquidsSL, AS, WSCFully soluble; added late to avoid interactions with undissolved dry products
8Add surfactants and adjuvantsNIS, COC, MSO, adjuvantAdded last — surfactants added too early can prevent proper dispersion of actives
9Top off with remaining water—Dilutes and mixes all products to final concentration; maintain agitation

⚠️ Always check individual product labels — some products specify a different addition sequence. When in doubt, add the product with the most restrictive label requirement first. See the full Mixing Order Guide for detailed guidance on each formulation type.

Jar test: how to check tank mix compatibility before filling your tank

A jar test (physical compatibility test) takes 15 minutes and can prevent a ruined tank, plugged nozzles, or reduced efficacy. Do one any time you use a new product combination — including pesticide + liquid fertilizer mixes.

  1. Use a clear 1-quart jar. A mason jar or transparent graduated cylinder works well.
  2. Add water first — about 1 pint — using the same water source as your tank (well water, municipal water, and pond water can have very different pH and hardness).
  3. Add each product in the WBAS order at the same proportion as the full-tank recipe. For a 300-gallon tank with 32 fl oz/tank of Product A, add about 0.1 fl oz (≈ 3 mL) to the 1-quart jar.
  4. Cap and invert the jar 10 times after each addition. Do not shake vigorously — gentle inversion mimics tank agitation.
  5. Let stand for 15–30 minutes and observe.
  6. Check for: separation into distinct layers (oily layer on top), gelling or thickening, visible precipitate or solid flakes at the bottom, or color change suggesting a chemical reaction.
  7. If the mixture stays uniform with no layers or solids — the mix is physically compatible. Proceed with the full tank.
  8. If separation or precipitation occurs — do not mix. Contact the product manufacturers or your agronomist for a compatible alternative.

Note: a jar test only confirms physical compatibility (no separation). It does not confirm biological compatibility (no antagonism between actives) or legal mix registration. Always check both product labels for tank mix restrictions.

Tank mix tips: getting the most from every load

Frequently asked questions

What does tank mix mean?

A tank mix is a combination of two or more pesticide or fertilizer products combined in the same spray tank and applied together in a single pass. Tank mixing is done to control multiple pests or weed species in one trip, broaden the spectrum of control, or add adjuvants that improve product performance. Every product in the mix must be registered for the target site, and the combination must be allowed under each product's label.

How do you calculate tank mix amounts?

The formula: amount per tank = label rate per acre × acres per tank, where acres per tank = tank size (gal) ÷ application rate (GPA). For example, a 300-gallon tank at 15 GPA covers 20 acres per tank. A product with a 32 fl oz/acre rate requires 32 × 20 = 640 fl oz per tank. The Tank Builder tab handles all unit conversions (pt, qt, lb, mL, L) automatically.

How do I calculate mix percentage?

Mix percentage = (volume of concentrate ÷ total tank volume) × 100. However, in agricultural spraying, oz per acre or oz per tank is the standard — not percentage — because percentage doesn't account for varying carrier volumes and can lead to incorrect dosing when GPA changes. Use this calculator to work in the same units as your product labels.

Can you mix herbicide and insecticide in the same tank?

Many herbicide + insecticide combinations are physically compatible and commonly used, but always verify with a jar test and check each label for tank mix restrictions. Some products explicitly prohibit certain combinations. Check the product manufacturer's tank mix guide or contact their tech line before mixing a new combination.

What is the Pivot Bio tank mix calculator?

Pivot Bio manufactures biological nitrogen products (PROVEN®, PROVEN40®) that have specific tank mix compatibility requirements. Pivot Bio recommends a compatibility check before tank mixing with fungicides or insecticides, as some chemistries can reduce live microorganism counts. This calculator computes the correct amounts for any tank mix including biologicals; always verify compatibility with Pivot Bio's own product guide before adding to a tank.

How do I calculate the volume of my spray tank?

Most commercial sprayer tanks are rated in gallons by the manufacturer and marked on the tank. If you need to verify actual capacity: fill to a known level using a flow meter, or measure the tank dimensions (cylindrical tank volume = π × r² × height, convert cubic inches to gallons by dividing by 231). The Volume Check tab lets you confirm your fill sequence adds up to your rated capacity.

What happens if you add products to the tank in the wrong order?

Adding products out of order can cause gelling, precipitation, or separation that is difficult or impossible to remix. For example, adding a surfactant before dry flowables can cause WDG granules to clump rather than disperse. Adding an EC before water is present can cause the emulsion to invert. Following the WBAS order listed in the mixing order section above prevents most common incompatibility issues.