How this calculator works
Labels give the rate as ounces of concentrate per gallon of spray, or per 1,000 square feet together with how much water to spray on that area. The concentrate for a tank is the tank size times the ounces per gallon. For a rate per 1,000 square feet, the ounces per gallon are the rate divided by the water used on 1,000 square feet.
Worked example: a label rate of 2 oz per gallon in a 2 gallon sprayer takes 4.0 fl oz of concentrate (8 tablespoons) per tank; in a 4 gallon backpack sprayer it takes 8 oz and in a 1 gallon one 2 oz. For a label rate of 3 oz per 1,000 ft² with 1 gallon of water per 1,000 ft², treating 5,000 ft² takes 15 oz of concentrate in 5 gallons of water, which is 3 tanks of 2 gallons (6.0 oz in each), and 10,000 ft² with a 4 gallon sprayer takes 30 oz and 3 tanks.
Concentrate per tank (fl oz)
By tank size and label rate in ounces per gallon.
| Tank | 0.5 oz/gal | 1 oz/gal | 2 oz/gal | 3 oz/gal | 4 oz/gal | 6 oz/gal |
|---|---|---|---|---|---|---|
| 1 gal | 0.5 | 1.0 | 2.0 | 3.0 | 4.0 | 6.0 |
| 2 gal | 1.0 | 2.0 | 4.0 | 6.0 | 8.0 | 12.0 |
| 3 gal | 1.5 | 3.0 | 6.0 | 9.0 | 12.0 | 18.0 |
| 4 gal | 2.0 | 4.0 | 8.0 | 12.0 | 16.0 | 24.0 |
| 5 gal | 2.5 | 5.0 | 10.0 | 15.0 | 20.0 | 30.0 |
Tips before you buy
- Read the label every time. Rates differ between products and between weeds, lawns and ornamentals.
- Mix only what you need. Left-over mix is hard to dispose of, and some products lose strength in the tank.
- Calibrate the sprayer once: spray a measured area of 1,000 ft² with water and see how much it uses, then you know the gallons per 1,000 ft² to enter.
- Add the concentrate to about half the water, then top up. Add products in the order the label says if you tank-mix.
- Wear the gloves, eye protection and clothing on the label, and keep children and pets off until it has dried.
Tools & materials for this project
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Frequently asked questions
How much concentrate per gallon of water?
Whatever the label says. At 2 oz per gallon a 2 gallon sprayer takes 4.0 oz, and a 1 gallon sprayer takes 2.0 oz.
How many tablespoons is an ounce?
There are 2 tablespoons in a fluid ounce, 6 teaspoons, and about 30 milliliters.
How do I convert ounces per 1,000 square feet to ounces per gallon?
Divide the rate by the gallons of water you apply per 1,000 ft². A rate of 3 oz per 1,000 ft² at 1 gallon per 1,000 ft² is 3 oz per gallon.
How much area does a 2 gallon sprayer cover?
At 1 gallon of water per 1,000 ft², 2,000 ft² per tank. Calibrate your own sprayer, since the output varies.
Can I use more than the label rate to be sure?
No. The label rate is the legal maximum, and more can harm plants, soil, pets and the environment, and it does not work better.
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Estimates only. Results assume standard materials and simple shapes. Supplier products vary, and the final call on quantity, structure and safety is yours. Check your local code and your supplier's guidance before ordering.