UNDERSTAND THE METHOD
Start with an estimate
This tool takes a daily energy estimate and a change that you choose. It subtracts the chosen amount and shows the resulting scenario. If the energy estimate is 2,400 kcal per day and the chosen change is 200 kcal, the displayed scenario is 2,200 kcal per day. The arithmetic is exact for those inputs. Your actual energy expenditure is uncertain, so the scenario is uncertain too.
Compare scenarios, not arrival dates
You can compare a maintenance view with one or more user-selected changes. Keep the original energy model and activity assumption visible beside each result. Do not convert a daily difference into an exact date or a fixed amount of future weight change. Body weight, energy use, and behavior can change over time. The National Institute of Diabetes and Digestive and Kidney Diseases uses a dynamic model for weight planning for this reason.
Know the scope
This tool is limited to educational arithmetic for adults aged 20–80. It does not assess a suitable intake or provide a personal weight-loss target. It excludes pregnancy and breastfeeding. Clinical conditions can need different assessment. No clinician review of this product is claimed. Use a qualified professional for personal nutrition decisions.
Keep the inputs with the result
Save the estimated maintenance value, the chosen change, the date, and the model used. A number without these fields is hard to interpret later. If your activity changes, create a new energy estimate and compare it with the old one. Use the macro tool only to convert a supplied calorie amount to grams; that calculation does not validate the amount.
Common questions
Will this tell me when I reach a weight?
No. A fixed subtraction does not account for changes in energy use or body weight.
Can I enter my own maintenance estimate?
Yes. A value you enter is labeled as an entered starting value. An estimate brought from the TDEE tool keeps its original model and inputs.
Is a displayed amount a diet recommendation?
No. It is subtraction using your chosen inputs. The tool does not assess whether that intake is safe or adequate.
Sources & limitations
Sources checked September 12, 2026. These notes explain published methods. They have not received an independent clinical review.
- NIDDK describes a dynamic body-weight model and excludes younger people, pregnancy, and breastfeeding from its planner.niddk.nih.gov
- Constant 3,500-calorie-per-pound predictions can overestimate weight loss because metabolism changes.niddk.nih.gov
- Energy equations have individual prediction error, so the starting energy estimate is uncertain.nationalacademies.org