###### Asked in Math and ArithmeticUnits of MeasureVolume

Math and Arithmetic

Units of Measure

Volume

# How many drops of water are in a gallon?

## Answer

###### Wiki User

###### August 06, 2014 9:55AM

According to the U.S.G.S. the average size of water droplet from a bathroom or kitchen faucet is about 1/4 of a milliliter (or CC), or 4,000 drops per liter; and about 0.0169 fl oz or 15,140 drops per gallon.

Some science measurements from droppers measure a drop much smaller, at 1/20th of a CC per drop, making the number of drops per gallon much higher.

20 drops/CC X 30 CC/fl oz X 128 fl oz/Gal = **76800**
drops/gal

In the end, it depends on the size of the drop as to how many drops there are in a gallon. For household leaks, 3-4 drops/CC is much more likely than 20-24 drops/CC that is often cited for scientific purposes.

## Related Questions

###### Asked in Math and Arithmetic, Units of Measure, Volume, Weight and Mass

### How many drops of water in one gallon?

Facts:
120 drops = 5mL
1 gallon = 3785 mL
* 90840 Drops in 1 Gallon
If a faucet dripped once a second how many gallons of water
would it waste?
It would waste 347 Gallons of water a year!
Facts:
1 year ~ 31,536,000 seconds
24 drops in 1 mL
1 gallon/3785 mL X (1 mL/24 drops) X (1 drop/ 1 s) X (31,536,000
s/ 1 year) = 347.1598415 gallons / year

###### Asked in Math and Arithmetic

### 1 million drops of water equals what volume?

Answer about 13 gallons depending on your assumptions of how
many drops per gallon.
Several methods to figure this out:
1 million drops of water is 1666.667 fluid oz. There are 600 drops
per fluid oz and 1,000,000 divided by 600 is 1666.667
(last digit is rounded)
1666.667 oz if about 13 U.S. gallons or if you prefer metric it
is
49.289 liters
Method 2
90840 Drops in 1 Gallon ( but that value depends on water temp and
other factors)
90840 Drops/1 gallon=1,000,000 drops/x gallons
90840x=1,000,000
x=11.0084 gallons
So this method gives 11 gallons and if we want to know how many
cubic inches that we note that:
1 gallon of water is 231 cubic inches. So 11.0084x231=2542 cubic
inches.
______
I found another professor give this example:
http://jwilson.coe.uga.edu/emt668/EMAT6680.Folders/Howard/Million.Drops.of.Water/Million.Drops.of.Water.html
10 drops of water = 1 milliliter and: 10,000 drops = 1 Liter then:
1,000,000 drops = 100 Liters and my reference quoted that: 1 Gallon
= 3.5 Liters, so 1,000,000 drops of water = 28.5714 gallons
Method 3
The example above 10 drops per ml, and of course you can easily
imagine that the size of a drop of water will not be uniform. It
depends on temperature and the dropper and many other
factors.
Most people use 15-20 gtts( drops) per ml, usually 20.
So the slightly larger value in this result comes from the fact
that the drops are much bigger, 10 per ml instead of 20. Divide
28.574 by 2 and the you have 14.2 gallons. Also 1 US gallon =
3.78541178 liters so using 3.5 is a low estimate.
So here is the same calculation as above using different
assumptions. The example below uses 3.785 liters per gallon and 20
drops per ml.
20 drops of water= 1 milliliter
20,000 drops = 1 liter
1 gallon is 3.785 liters.
so
(20,000 drops/1 liter)(3.785 liter/1 gallon)=75,700
drops/gallon
(compare this to 90840 used in the first part above)
75,700 drops/gallon=1,000,000 drops/X gallons.
Solve for x
75,700X=1,000,000
and the answer is 100, 000 drops is 13.21 gallons

###### Asked in Pollution

### How many drops of oil does it take to pollute a gallon of water?

A standard measure of oil pollution in water is 10 ppm (10 parts
oil per 1,000,000 parts water). As a gallon of water weights 10 lbs
(Imperial gal) or 8 lb (US) gal) the weight od a gallon is about
4.54 kg, or 4540 gm and there are usually thought to be 40 drops in
a ml a drop of oil weighs about 0.02 gm.
So 1 drop in gallon would be 0.02 gm in 4540 gm or 1 gm in 225000
gm (4 ppm). Indicating that 2.5 drops would pollute 1 gallon of
water to the 10 ppm level

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