Sometimes you need a quick way to calculate how many Weight Watchers’ points are in your food when all you know is the number of calories. I realized soon after starting the Weight Watchers’ diet that a point was worth about 40 calories give or take a few calories. But Zama Jr. just hates it when I try to figure points from calories and argues it is way more complex than that— the Weight Watchers’ formula considers the mix of carbohydrates, proteins, fats and fiber in each particular food. She is so right, but like it or not there is a relationship between calories and points and I set out to find the relationship and to show Zama Jr. that 40 calories per point is a pretty fair estimate. For those who don’t care how it’s figured but just how to do it, here is the way.
How to calculate Weight Watcher points from calories only:
Number of Calories divided by 40= Number of PointsPlus®
(always round your answer up and add an extra point if high in fat and carbs)
120 calories÷40=3 points
150 calories÷40=3.75 points- round-up to 4
490 calories÷40=12.25 points- round-up to 13
But what about the fiber? For the most part just ignore the fiber but if you’re calculating something like beans with a lot of fiber then feel free to round your number down to the closest point instead of up.
Click on the image to open a .pdf file with credit card size printing dimensions. Print on card stock or have it laminated at your local office store for long-lasting use.
Want to know how to it was calculated?
- Step 1: First I looked at the number of calories in a gram of fat, protein and carbohydrates. They are:
9 calories per gram of Fat
4 calories per gram of Carbohydrates
4 calories per gram of Protein
The website, www.caloriesperhour.com, gives a good tutorial on all things caloric.
- Step 2: I calculated how many grams of fat were in a 1000 calories by dividing 1000 by 9. 1000÷9=111.1111 grams.
- Step 3: Calculate the number of Watchers points in 111.1 grams of fat. Answer: 29
- Step 4: Divide 1000 calories by 29 to get the number of fat calories in 1 point. 1000÷29=34.4828 calories per point.
- Step 5: Repeat for protein , using the number 4 instead of 9. 1000÷4=250; 250 grams of protein= 23 points; 1000 calories÷23 points= 43.47 calories per point.
- Step 6: Repeat for carbohydrates, again using the number 4. 1000÷4=250; 250 grams of carbohydrates= 27 points; 1000 calories÷27 points= 37.03 calories per point.
- Step 7: So we now know that a point made up of all fat has 34.4 calories; of all protein has 43.47 calories; and an all carbohydrate point has 37.03 calories. We add these three numbers and divide the answer by 3 to get the average number of calories per point. 34.48+43.47+37.03=114.98 ÷3= 38.32 calories per point overall.
- Step 8: I round the 38.32 to 40 and forget about the fiber (unless there is a lot of fiber) and remember to always round UP.
Checking the Numbers
I tested my estimator on about 50 products and most were spot on. However, you can see from the chart to your left that foods composed mostly of fats and carbohydrates will average less than 40 calories a point. This is particularly true of dessert items so be sure to add an extra point for these. When doing a large recipe, do each ingredient separately to get a more exact count or use an official points calculator if you have one available.
Calculating Weight Watchers’ Activity Points
The calorie to point estimator can also be used for calculating activity points. If your treadmill indicates the calories you’ve used then divide the number by 40 and you’ll get the number of activity points. Example: 80 calories burned would equal 2 activity points— ( 80 ÷ 40=2). I’d be cautious and round your answers down instead of up when calculating activity points. Zama’s Point Estimator card can help with this too.