So you’ve finished counting, but what’s really there?

As you exhale, the stress starts to melt away. You’ve just finished taking liquor inventory, and we know there are few better feelings. But wait—managing a profitable bar program shouldn’t stop there.

After working to mark down the percent of liquor in each of your bottles in BevSpot, you’ve got a good idea of what you’re sitting on. But exactly how many drinks are really left in those bottles? Being able to quickly translate those percentages into a specific number of cocktails will give you a whole new understanding of your program, and make you a savvier bartender.

bar math equations cheat sheet BevSpot

Preparing Your “Bottle to Drink” Measuring Stick

To calculate how many drinks you can get out of each bottle, we need to know how many ounces are actually in some of the most standard bottle sizes that we see. We do this by dividing the volume of the bottle by one ounce:

Number of 1-oz servings = bottle volume ÷ 1 oz

Though there are many varying liquor bottle sizes, but the ones most commonly used by BevSpot users are 750 mL and 1L bottles. The 750 mL bottle is probably the most common for all spirits and wines, so let’s use that as an example.

Let’s say your drink demands 1 oz of a certain spirit. One U.S. Fluid Ounce (oz.) is equal to 29.57 mL. Let’s do some simple math. (Trust me, if I can do it you’ll be fine.)

750mL ÷ 1 oz = 750 mL ÷ 29.57 mL = 25.36 1-oz servings

Judging by that, there are 25.36 1-oz servings per 750mL bottle (or 25 if you want to round down to a full number). This equation will work for any bottle size that is listed in milliliters on your bar:

1000mL ÷ 1 oz = 1000 mL ÷ 29.57 mL = 33.81 1-oz servings

Measuring How Many Drinks Are In A Partially Full Bottle

Now that you know how many 1-oz servings are in each of your bottles, it’s time to dig a little deeper. How many ounces of each base spirit are you pouring in each drink you serve? Is it 1.5 oz, 2 oz, or 3 oz? Whatever the pour size, it’s easy to translate that into a number of drinks once you know the percentage of the bottle that remains. (These examples are just for spirits, but can easily be applied to wines by the glass or even draft beer.)

To do this, multiply the number of servings in a full bottle by the percentage of the bottle that remains:

Drinks in partially full bottle = Drinks in full bottle × % remaining

For this example, say that I use a 1-oz pour of my spirit in a cocktail, and I have 40% of my 750ml bottle of that spirit (that is, I have 40% of 25.36 1-oz servings in my bottle):

25.36 servings × 40% = 25.36 servings × 0.4 = 10.14 1-oz servings

Measuring Drinks With A Different Pour Size

But what if your cocktail asks for a different amount of a spirit? Then we need to know how many servings of that new pour amount exist in that bottle. We can find this by dividing the number of remaining 1-oz pours by the new pour size (in ounces):

Servings of new pour size = Number of 1-oz servings ÷ new pour size in ounces

Let’s take a 2-oz pour as the example. Now we know I have 10.14 1-oz servings of liquor left, I just need to divide that by my 2-oz base pour to know how many drinks of the new pour size remain:

10.14 1-oz servings ÷ 2 oz = 5.07 2-oz servings

There we go—in this case, I’ve got about 5 full drink pours left in that bottle.

Drink Measuring Conversion Cheat Sheet

Of course, different drinks are going to call for different amounts of liquor, but with this flow and the handy cheat sheet below you can always know how many more full portions you have in each of those bottles. This will help you better stock your bar pre-shift, make smarter purchases every week, and hopefully help you increase your profits across your entire bar program.