Home Ratio to Ounces Calculator

Ratio to Ounces Calculator: Oz Per Gallon Converter

Convert any mixing ratio to exact ounces per gallon and tank amounts. For a final gallon, 1:16 = 7.53 fl oz, 1:32 = 3.88 fl oz, and 1:64 = 1.97 fl oz. Enter any ratio and tank size for fl oz, mL, tbsp, and tsp outputs.

Looking for the general tool? Use the Spray Mix Calculator · Prefer oz/gal inputs? Oz Per Gallon Calculator · Want a printable table? Mixing Chart · Hose-end sprayer? Dial N Spray settings.

Calculator

Convert Ratio → Ounces of Concentrate

Enter your final spray volume and ratio. The calculator returns the exact concentrate amount in fl oz (plus mL, tbsp, and tsp) and the water amount to fill the tank.

For small amounts (under 4 oz), a measuring syringe↗ is more accurate than a kitchen spoon. For larger volumes, use a graduated cylinder↗.

How to convert a ratio to ounces

  1. Choose container units: Select US (gal / fl oz) or Metric (L / mL).
  2. Enter final spray volume: Type the total amount you want to mix and choose the unit.
  3. Select the ratio format: Choose Concentrate:Water (1:X) or Water:Concentrate (X:1) to match the label.
  4. Enter the ratio value (X): For 1:32 enter 32. For 64:1 (water:concentrate) enter 64 in X:1 mode.
  5. Read the results: Measure the concentrate (fl oz + mL + tbsp/tsp) and add water to reach final volume.

If your label gives oz per gallon instead of a ratio, use Oz Per Gallon Calculator.

Ratio to ounces per gallon: 1:16, 1:32, 1:64 and more

Quick reference for a 1 gallon sprayer. For any other tank size, use the calculator above.

Mixing ratio Oz per gallon Metric (mL/L) Common use
1:8 14.22 fl oz 111 mL Heavy-duty cleaners, disinfectants
1:16 7.53 fl oz (≈ 8 oz) 59 mL Concentrated cleaners, strong herbicides
1:32 3.88 fl oz (≈ 4 oz) 30 mL Standard pesticide and herbicide rates
1:64 1.97 fl oz (≈ 2 oz) 15 mL Lawn fertilizers, mild pesticides
1:100 1.27 fl oz 10 mL Dilute foliar feeds, light sanitizers
1:128 1.00 fl oz 8 mL Light cleaning solutions

Ratios assume concentrate:water (1:X). Formula: oz/gal = 128 ÷ (1 + X). For exact values at any tank size, use the calculator above.

What is the 2 oz per gallon ratio?

2 oz per gallon equals a 1:63 ratio (concentrate:water), commonly listed as 1:64. For a 1-gallon sprayer: 2 fl oz concentrate + ~126 fl oz water. For a 4-gallon backpack: 8 fl oz concentrate total.

What is the 4 oz per gallon ratio?

4 oz per gallon equals a 1:31 ratio, commonly listed as 1:32. For a 1-gallon sprayer: 4 fl oz (½ cup) concentrate + ~124 fl oz water. For a 4-gallon backpack: 16 fl oz (1 pint) concentrate total — see the Backpack Sprayer Calculator for full tank instructions.

What is the 8 oz per gallon ratio?

8 oz per gallon equals a 1:15 ratio, commonly listed as 1:16. For a 1-gallon sprayer: 8 fl oz concentrate + ~120 fl oz water. For a 4-gallon backpack: 32 fl oz (1 quart) concentrate total.

Why 1:32 is 3.88 oz per gallon — not exactly 4 oz

A ratio written as 1:32 concentrate:water has 33 total parts. One final US gallon has 128 fl oz, so the concentrate amount is 128 ÷ 33 = 3.88 fl oz. Rounding that to “4 oz per gallon” is convenient field shorthand, but 4 oz concentrate plus 124 oz water is mathematically an exact 1:31 ratio.

The same distinction applies to other familiar pairs: 1:64 = 1.97 oz/gal, while exactly 2 oz/gal is 1:63; 1:16 = 7.53 oz/gal, while exactly 8 oz/gal is 1:15. When a product label gives a ratio, calculate from the ratio. When it gives oz/gal, use that oz/gal number directly.

1:32 and 1:64 tank examples

Tank size1:32 concentrate1:64 concentrate
1 gal3.88 fl oz1.97 fl oz
2 gal7.76 fl oz3.94 fl oz
4 gal15.52 fl oz7.88 fl oz
5 gal19.39 fl oz9.85 fl oz

Use the calculator above for any other ratio, tank size, or metric volume.

Hose-end sprayer dilution: how Dial N Spray settings work

A hose-end sprayer is different from a tank sprayer. The reservoir holds concentrate while the sprayer meters product into the hose water as you spray. Because of that, the final tank-volume math above should not be used to calculate how much product to pre-mix in a hose-end reservoir.

For an Ortho Dial N Spray, use the application amount on the product label and set the dial to the corresponding amount. Ortho says the current Dial N Spray has 14 dial settings and is designed to automatically meter liquid concentrates. See the Ortho Dial N Spray instructions.

Do not treat the reservoir size as final spray volume. A 32 fl oz reservoir does not mean you are making 32 fl oz of finished spray. The hose supplies the carrier water during application.

If your label gives ounces per gallon

Match the label's ounces-per-gallon rate to the hose-end sprayer setting. If the product label provides model-specific hose-end directions, those directions take priority.

If your label gives a dilution ratio

First convert the ratio to its exact oz/gal equivalent with the calculator above, then use the sprayer and product instructions to choose a setting. For a dedicated hose-end workflow, use the Dilution Calculator and its Hose-End mode.

Pesticide directions, rates, equipment restrictions, and mixing instructions come from the label. EPA's pesticide label guidance explains why the label instructions control.

Recommended measuring tools

Small ratios like 1:64 require precise measurement — kitchen spoons introduce significant error at low volumes:

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FAQ

How many ounces of concentrate is 1:32 per gallon?

For a 1 gallon final mix, a 1:32 dilution ratio (concentrate:water) is about 3.88 fl oz of concentrate (≈ 115 mL). If your sprayer is 2 gallons, 3 gallons, or a metric tank, use the calculator above for exact values.

How many ounces of concentrate is 1:16 per gallon?

For a 1 gallon final mix, 1:16 is about 7.53 fl oz of concentrate (≈ 223 mL). This is a stronger mix than 1:32 or 1:64 because it uses more concentrate per gallon.

How many ounces of concentrate is 1:64 per gallon?

For a 1 gallon final mix, 1:64 is about 1.97 fl oz of concentrate (≈ 58 mL). This is a weaker dilution than 1:32.

Is 64:1 the same as 1:64?

Not always. Many labels use different ordering. 1:64 commonly means 1 part concentrate to 64 parts water. 64:1 often means 64 parts water to 1 part concentrate. Use the calculator’s ratio format selector to match the label.

Can I convert a mixing ratio to tablespoons, teaspoons, and mL?

Yes. This ratio to ounces calculator also shows approximate conversions to mL, tablespoons (tbsp), and teaspoons (tsp)—handy for small pump sprayers and spray bottles.

Does this replace pesticide label instructions?

No. This page provides mixing math and unit conversions only. Always follow the product label for approved uses, application rates, timing, and safety guidance.

How do I use a hose-end sprayer dilution calculator?

For a hose-end sprayer, do not enter the reservoir size as though it were the final mixed spray volume. The sprayer meters concentrate into hose water during application. Match the product label's oz/gal rate to the sprayer setting, or convert a label ratio to oz/gal first. For Ortho Dial N Spray, follow the product label and the sprayer's dial instructions.

How the math works

For a ratio written as 1:X (concentrate:water), the concentrate fraction of the final mix is 1 ÷ (1 + X). Multiply that fraction by your final spray volume to get the concentrate amount. The rest is water.