Spray Mix Calculators Ounces Per Gallon Calculator

Oz Per Gallon Calculator: Convert Oz/Gal to Ratio (and Back)

Convert oz per gallon into a 1:X ratio, convert ratios back into oz/gal, and calculate the total concentrate needed for any tank size.

🎯 Quick oz per gallon answers:

  • How many ounces per gallon is 1:16? = 7.53 oz per gallon
  • How many ounces per gallon is 1:32? = 3.88 oz per gallon (~4 oz)
  • How many ounces per gallon is 1:64? = 1.97 oz per gallon (~2 oz)
  • How many ounces per gallon is 1:128? = 1 oz per gallon

Use calculator below for other ratios and tank sizes.

On this page: Calculator · Quick reference table · Related calculators · FAQ

Common label examples: 2 oz per gallon · 1:32 · 1:64. Use Tank total mode for backpack/ATV sprayers.

Prefer ratio inputs? Ratio to Ounces · Want a printable ounces per gallon table? Mixing Chart · Need full mixing? Spray Mix Calculator.

Calculator

Oz/gal ↔ Ratio, plus Tank Totals

Pick a mode and enter your label value. Results include fl oz, mL, and small-measure help (tbsp/tsp).

Note: Many labels intend oz/gal as ounces of concentrate per final gallon of spray mix. If your label says "per gallon of water" or "per finished gallon," follow that wording.

🧰 Measuring small amounts accurately?
A chemical measuring cup or graduated cylinder prevents costly mixing errors. See all recommended spray equipment.

Oz per gallon vs ratio: what’s the difference?

Some labels give a rate (like 2 oz per gallon), while others give a ratio (like 1:32). They can describe the same mix — you just need to convert formats. Not sure how to read your label? See our label dilution guide.

If you have a ratio and want ounces, use ratio → oz/gal. If you have ounces and want a ratio, use oz/gal → ratio.

Ounces per gallon for different tank sizes

When labels specify ounces per gallon, multiply by your tank size to get total concentrate needed:

Example: 2 oz per gallon for different sprayers

Example: 4 oz per gallon for different sprayers

Pro tip: For small bottles (16-32 oz), use the Handheld Spray Bottle Calculator for tablespoon and teaspoon measurements.

How to use oz per gallon

  1. Choose a mode: Use oz/gal → ratio, ratio → oz/gal, or tank total.
  2. Enter your label value: Type the label’s oz per gallon, or enter the ratio value X for 1:X.
  3. Optional: add tank size: If you want total concentrate, enter your tank size in gallons.
  4. Measure and mix: Measure concentrate, then add water to reach the final volume. Follow the label for mixing order and agitation.

Want a quick table for common ratios? See the Spray Mixing Chart.

Quick reference: common ratios in oz per gallon

Assumes ratio is concentrate:water (1:X) and values are rounded. For exact values (and any ratio), use the calculator above.

Ratio (1:X) Oz per gallon (fl oz/gal) mL per liter (mL/L)
1:16 7.53 58.82
1:32 3.88 30.30
1:64 1.97 15.38
1:100 1.27 9.90

More ratios: Spray Mixing Chart.

Complete ounces per gallon chart (all common mixing rates)

This chart shows ounces per gallon for all standard spray mixing ratios:

Ratio
(Concentrate:Water)		 Ounces Per Gallon
(fl oz/gal)		 For 1 Gallon
Final Mix		 For 4 Gallon
Backpack Sprayer
1:8 14.22 oz/gal 14.22 fl oz concentrate 56.89 fl oz concentrate
1:10 11.64 oz/gal 11.64 fl oz concentrate 46.55 fl oz concentrate
1:16 7.53 oz/gal 7.53 fl oz concentrate 30.12 fl oz concentrate
1:20 6.10 oz/gal 6.10 fl oz concentrate 24.38 fl oz concentrate
1:32 3.88 oz/gal 3.88 fl oz concentrate 15.52 fl oz concentrate
1:50 2.51 oz/gal 2.51 fl oz concentrate 10.04 fl oz concentrate
1:64 1.97 oz/gal 1.97 fl oz concentrate 7.88 fl oz concentrate
1:100 1.27 oz/gal 1.27 fl oz concentrate 5.06 fl oz concentrate
1:128 1.00 oz/gal 1 fl oz concentrate 4 fl oz concentrate
1:256 0.50 oz/gal 0.5 fl oz concentrate 2 fl oz concentrate

Reverse chart: oz per gallon to ratio conversion

If your label lists ounces per gallon and you want the equivalent ratio:

Ounces Per Gallon Equivalent Ratio
(Concentrate:Water)		 Common Use
0.5 oz per gallon 1:256 Very light dilutions, sanitizers
1 oz per gallon 1:128 Light cleaning, mild applications
2 oz per gallon 1:64 Lawn fertilizer, light herbicides
3 oz per gallon ~1:43 Moderate pesticide applications
4 oz per gallon 1:32 Standard pesticide, herbicide rates
5 oz per gallon ~1:26 Stronger herbicide applications
6 oz per gallon ~1:21 Concentrated treatments
8 oz per gallon 1:16 Heavy-duty cleaners, strong herbicides
10 oz per gallon ~1:13 Very concentrated applications
12 oz per gallon ~1:11 Industrial strength cleaners

For any custom oz per gallon amount (including decimals like 2.5 oz/gal or 3.7 oz/gal), use the calculator above for exact ratio conversions and tank totals.

Oz to 1 gallon ratio: quick answers

If your label says a specific number of ounces to 1 gallon, here are the equivalent mixing ratios:

For other amounts or multi-gallon tanks, use the calculator above.

FAQ

How many ounces per gallon is 1:16?

1:16 (concentrate:water) equals 7.53 ounces per gallon. For a 1-gallon spray tank, mix 7.53 fl oz of concentrate with approximately 120.5 fl oz of water. For a 4-gallon backpack sprayer, use 30.12 fl oz (about 30 oz or 1.9 cups) of concentrate.

How many ounces per gallon is 1:32?

1:32 (concentrate:water) equals 3.88 ounces per gallon, commonly rounded to 4 oz per gallon. For a 1-gallon tank, use 3.88 fl oz concentrate. For a 4-gallon backpack sprayer, use 15.5 fl oz (just under 1 cup) of concentrate. This is one of the most common pesticide and herbicide mixing rates.

How many ounces per gallon is 1:64?

1:64 (concentrate:water) equals 1.97 ounces per gallon, commonly rounded to 2 oz per gallon. For a 1-gallon tank, use 2 fl oz concentrate. For a 4-gallon backpack sprayer, use 8 fl oz (1 cup) of concentrate. This ratio is common for lawn fertilizers and light herbicide applications.

How many ounces per gallon is 1:128?

1:128 (concentrate:water) equals exactly 1 ounce per gallon. For a 1-gallon tank, use 1 fl oz concentrate. For a 4-gallon backpack sprayer, use 4 fl oz (¼ cup) of concentrate. This very dilute ratio is used for light cleaning solutions and some foliar applications.

What is 2 oz per gallon in a ratio?

2 ounces per gallon equals a 1:64 ratio (concentrate:water). This is calculated as: 2 oz concentrate per 128 oz total = 2:126, which simplifies to approximately 1:63 or exactly 1:64 for standard mixing. For a 4-gallon backpack sprayer at 2 oz per gallon, use 8 fl oz of concentrate total.

What is 4 oz per gallon in a ratio?

4 ounces per gallon equals a 1:32 ratio (concentrate:water). More precisely, it's 3.88 oz per gallon for an exact 1:32 ratio, but 4 oz per gallon is the common approximation. For a 4-gallon backpack sprayer, use 16 fl oz (1 pint or 2 cups) of concentrate total.

What is 8 oz per gallon in a ratio?

8 ounces per gallon equals a 1:16 ratio (concentrate:water). More precisely, it's 7.53 oz per gallon for an exact 1:16 ratio, but 8 oz per gallon is a common approximation for stronger mixes. For a 4-gallon backpack sprayer, use 32 fl oz (1 quart or 4 cups) of concentrate total.

How do I convert oz per gallon to a 1:X ratio?

For a 1 gallon final mix (128 fl oz), the concentrate fraction is: (oz per gallon ÷ 128). Convert that to 1:X using X = (1 ÷ fraction) − 1. This calculator does it for you.

How many ounces per gallon is a 1:32 mix?

For concentrate:water ratios, 1:32 corresponds to: 128 ÷ (1 + 32) ≈ 3.88 fl oz per gallon. Use the calculator for exact values.

How do I calculate total concentrate for a 4 gallon tank?

Multiply your label rate by tank gallons: oz/gal × gallons. Example: 2 oz/gal × 4 gal = 8 oz of concentrate.

Does oz/gal mean concentrate per gallon of water or per final gallon?

Usually it means per final gallon of spray mix, but labels vary. If the label is unclear, verify the intended method with the manufacturer.