I see people posting a lot about how to calculate a caloric deficit and even left a comment on someone else’s post, but I want to get the information out to as many people so I will repost it here. It is a 3 step process and you can follow it here.

Step 1: Calculate your RMR (resting metabolic rate)
This is your metabolic rate at rest. It’s important to get a baseline because our bodies require energy to even do involuntary actions such as breathing, heart beat, etc. This is required for life! This does not take into consideration your activity level.

There are two different formulas for each sex since men burn more metabolically. I use the Mifflin-St Jeor equation but there are a couple other ones you can use.

if you identify as a different gender, use your assigned sex at birth for this part

Males: 10 × weight (in kilograms) + 6.25 × height (in centimeters) – 5 × age (in years) + 5

Females: 10 × weight (in kilograms) + 6.25 × height (in centimeters) – 5 × age (in years) – 161

Plug in that number that you got for your RMR here to use for the next step.

Step 2: Calculate your TDEE (total daily energy expenditure)
This is your energy needs based on your activity level
Your activity can be estimated by a scale

1.2: sedentary (little to no activity)
1.375: lightly active (light exercise 1-3 days)
1.55: moderately active (moderate exercise 3-5 days per week)
1.725: very active (hard exercise 6-7 days per week)
1.9: extra active (very hard exercise two or more times per day, training, or a physical job)

Which ever one is you, plug it into the formula
RMR x activity level= kcals needed to maintain weight

The number you get here is used to determine maintenance calories.

Step 3: Create a deficit between 250-500 kcals per day for a 0.5lb-1lb loss respectively from the number you got for your TDEE.
Anything more than 500 kcal deficit can be unhealthy and lead to malnutrition and muscle loss.

With the maintenance calories you calculated, subtract the deficit.

Here’s an example with all the steps put together:

Step 1: Calculate RMR
10 x 70 + 6.25 x 162.56 - 5 x 23 -161 =1440 kcals for RMR (cals for basic bodily functioning)

Step 2: Calculate TDEE
1.55 (1440)= 2232 kcals for TDEE (maintenance cals)

Step3: Calculate your caloric deficit
2232 kcals - 500 kcals= 1732 kcals (~1lb loss per week)
2232 kcals - 250 kcals= 1982 kcals (~0.5lb loss per week)

DO NOT do anymore than a 500 kcal deficit as aforementioned. This is harmful and restrictive. a 0.5-1lb loss each week is healthy and sustainable.

Remember to always consult a medical professional before you make any new changes to your diet/exercise and to be cautious of information people put out. Everyone will have different numbers for their own energy needs. Weight loss is not linear as there are many factors that play into someone’s ability to lose weight, these are just numbers to get an idea of where you may be.