There is no validated PCOS-specific TDEE formula, so the standard Mifflin–St Jeor equation and activity factors are used to estimate maintenance calories. For weight management, the 2023 international PCOS guideline recommends a tailored energy deficit based on your energy needs, body weight and activity; the earlier 2018 guideline gave a 30% or 500–750 kcal/day starting point. A 30-year-old woman, 5′5″ and 165 lb, who is moderately active has a TDEE of about 2,277 kcal.
Key takeaways
- Standard equations are used for PCOS because no PCOS-specific energy equation has been validated; treat the result as an estimate and check it against your weight trend.
- The 2023 international guideline recommends a tailored energy deficit; the earlier 2018 guideline gave a common starting point of a 30% or 500–750 kcal per day deficit.
- For a 30-year-old woman at 165 lb who is moderately active, TDEE is about 2,277 kcal, and the 2018 starting-point range works out to roughly 1,527–1,777 kcal.
- Deficits should be individualised: for a heavier, less active woman a 750 kcal deficit can fall below her BMR, which needs professional input.
How this PCOS calorie calculator works
Enter your age, weight, height and activity level. The calculator is set to female with a starting age of 30, and it estimates BMR with Mifflin–St Jeor (Mifflin et al., 1990) before multiplying by an activity factor to give TDEE. You can choose lose, maintain or gain, with fat-loss paces of 10%, 15% or 20% below TDEE.
This page describes calorie math only. It is not medical advice and does not diagnose, treat or monitor polycystic ovary syndrome. If you have PCOS, talk with your doctor or a registered dietitian before changing your diet.
Is there a different TDEE formula for PCOS?
No validated PCOS-specific formula is in use here. The calculator applies the same equations and activity factors it uses for any adult woman, which means the result is an estimate for a typical person of your age, size and activity. Your actual maintenance might sit above or below it. The best check is your own weight trend over several weeks, which the adaptive TDEE calculator can turn into a measured number.
What does the PCOS guideline say about calorie deficits?
The 2023 international PCOS guideline recommends a tailored energy deficit based on your energy needs, body weight and activity (Teede et al., 2023). It sets no calorie number. The earlier 2018 guideline gave a common starting point of a 30% or 500–750 kcal/day deficit (Teede et al., 2018). TDEECalc’s built-in paces stop at 20% below TDEE, so to see a 30% figure, multiply your TDEE by 0.7. Beyond this energy recommendation, this page does not interpret the guideline or make claims about specific diets.
What does that look like in numbers?
The right deficit depends on size and activity, so here are two examples, both 30-year-old women at 5′5″. The deficit columns illustrate the 2018 guideline figures, not values from the current guideline:
| Example | BMR | TDEE | −500 kcal | −750 kcal | −30% |
|---|---|---|---|---|---|
| 165 lb, moderately active (×1.55) | 1,469 | 2,277 | 1,777 | 1,527 | 1,594 |
| 190 lb, lightly active (×1.375) | 1,583 | 2,176 | 1,676 | 1,426 | 1,523 |
For the 190 lb woman, a 750 kcal deficit lands at 1,426 kcal, below her BMR of 1,583 kcal, while 30% of her TDEE is 1,523, also below her BMR. This is one reason the 2023 guideline calls for a tailored deficit, and why a smaller deficit, or professional supervision, may be the better route. As a general rule, avoid planning below about 1,200 kcal, or below BMR for long, without medical supervision. Compare paces side by side in the calorie deficit calculator.
How long will weight loss take?
Dynamic modelling shows weight loss slows as the body gets lighter, so a fixed daily intake yields progressively smaller weekly changes (Hall et al., 2011). The weight loss calculator projects this week by week from your calories. Real results vary, and a pace that fits your life and health matters more than a perfect projection.
What should I check before starting?
- Talk to a clinician about your plan, especially if you take any medication.
- Check your intake against the floors: about 1,200 kcal for women, and not below your BMR for long.
- Watch for warning signs, such as dizziness, missed meals driven by restriction or a history of disordered eating. Seek support if these apply.
- Use a long enough window, two to four weeks, before judging any target against your scale trend.
General guidance on healthy eating patterns is available in the Dietary Guidelines for Americans (Dietary Guidelines 2020–2025). Anything specific to PCOS, such as which foods or supplements to choose, is a question for your clinician.
What about other health conditions?
If you have thyroid disease, diabetes, a history of an eating disorder, or are pregnant, trying to conceive or breastfeeding, calculator estimates may not suit you. See the breastfeeding calorie calculator for lactation. Always follow your own care team’s advice over any online tool.
Frequently asked questions
Do women with PCOS have a slower metabolism?
This page does not claim so. The calculator uses the same equations as for everyone because no PCOS-specific equation is validated. If your weight trend differs from the estimate, believe the trend and adjust, and discuss the pattern with your clinician.
How many calories should I eat with PCOS to lose weight?
The 2023 guideline recommends a tailored energy deficit based on your energy needs, body weight and activity, with no fixed calorie number. The earlier 2018 guideline gave a 30% or 500–750 kcal/day starting point, which for the example woman (TDEE 2,277 kcal) is about 1,527–1,777 kcal. Work out your own TDEE here, then agree a target with your doctor or dietitian.
Is a low-carb diet better for PCOS?
This page does not make dietary pattern claims. The calculator covers energy only. Questions about carbohydrate intake, insulin resistance and medication belong with your clinician or a registered dietitian who knows PCOS.
Can I use the TDEE calculator if I have PCOS?
Yes, as an estimate of energy needs, like any other adult. It does not diagnose or monitor PCOS. Use the TDEE calculator for women for the general version and the calorie deficit calculator to compare paces.
Is a 750 calorie deficit too much?
It can be. The 2018 guideline's starting point was 500–750 kcal, and the 2023 guideline says the deficit should be tailored. A larger deficit relative to your size can push intake below your BMR or the 1,200 kcal floor. The calculator warns you in those cases. Smaller deficits are common and safer to start with.
References
- Teede HJ, Tay CT, Laven JJE, et al. (2023). Recommendations from the 2023 International Evidence-based Guideline for the Assessment and Management of Polycystic Ovary Syndrome. Journal of Clinical Endocrinology & Metabolism 108(10):2447–2469.
- Teede HJ, Misso ML, Costello MF, et al. (2018). Recommendations from the international evidence-based guideline for the assessment and management of polycystic ovary syndrome. Fertility and Sterility 110(3):364–379.
- Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO (1990). A new predictive equation for resting energy expenditure in healthy individuals. American Journal of Clinical Nutrition 51(2):241–247.
- U.S. Department of Agriculture and U.S. Department of Health and Human Services (2020). Dietary Guidelines for Americans, 2020–2025 (9th ed.). DietaryGuidelines.gov.
- Hall KD, Sacks G, Chandramohan D, et al. (2011). Quantification of the effect of energy imbalance on bodyweight. The Lancet 378(9793):826–837.