How do you choose a starting calorie target?
Begin with a maintenance estimate using your current body measurements and normal activity. Maintenance means the approximate daily intake associated with keeping your current weight under those circumstances. Resting energy is only one part of total expenditure.
Estimate a starting weight-loss intake
Enter your measurements to see maintenance and a starting intake with a visible 500 kcal/day reduction. You can edit that assumption.
Complete the fields, then calculate to see the method and result.
Mifflin–St Jeor, 1990 · NHLBI adult weight-management evidence review, 2013 · Method reviewed .
The calculator uses Mifflin–St Jeor resting energy × your activity assumption, then subtracts 500 kcal/day by default. That reference comes from adult overweight/obesity guidance, not a measurement of the deficit best suited to you. You can edit the reduction up to 750 kcal/day. This tool withholds loss targets for BMI below 25 and outputs below 1,200 kcal/day with the female coefficient or 1,500 with the male coefficient. Those are disclosed tool boundaries, not a guarantee that an accepted result is appropriate or nutritionally adequate. It does not save a target to IZeat.
The NHLBI adult overweight/obesity evidence review describes calorie-restricted interventions and intake ranges used in those programs. We use a 500 kcal/day scenario as a transparent starting reference, retain a cap of 750, and use the lower ends of the reported intake ranges as display boundaries. These choices do not replace individual assessment; BMI alone cannot decide whether weight loss is appropriate.
If you already have a target from a clinician or registered dietitian, keep that context rather than replacing it with a generic calculator. Otherwise, an appropriate planning tool can help you explore a starting scenario.
For an additional projection that includes a goal weight and time frame, the NIDDK Body Weight Planner is an optional next step. The starting intake above does not depend on using it:
- Enter your current weight, age, height and sex using consistent units. Use its activity-estimation control to describe the routine you actually have.
- Enter a goal weight and an initial time frame. Treat these as a scenario to inspect, not a commitment to reach a number on that date.
- Leave activity unchanged unless you genuinely intend a change; a plan that assumes added activity will depend on that change.
- Continue to the results and identify the goal-phase daily intake. Keep the current-maintenance and later-maintenance outputs separate: neither is the intake for the loss phase.
- Read the warnings and inspect whether the projected intake can fit an adequate, workable eating pattern. If the goal or intake produces a warning, give the scenario more time or revise the goal and recalculate. Do not change an activity assumption solely to obtain a preferred calorie number.
The external planner’s goal-phase output is a separate scenario to compare with the on-page starting estimate. The models and assumptions differ, so the outputs need not match. Keep the planner’s current-maintenance, goal-phase and later-maintenance figures distinct; an unwarned result is still not proof of an adequate diet.
Keep both the inputs and outputs. Compare a longer time frame while holding the other inputs constant, then decide whether the revised scenario is more workable. The modeled date remains a projection; this is not a guarantee of a particular weight or an instruction to keep cutting intake.
The daily calorie needs guide addresses maintenance. The existing deficit calculation guide explains the arithmetic in detail. This page focuses on turning a starting estimate into a plan you can review.
What does the subtraction actually tell you?
Resting energy = 10 × weight (kg) + 6.25 × height (cm) − 5 × age + coefficient (+5 or −161). Maintenance = resting energy × activity assumption. Starting intake = maintenance − planned reduction. A worked calculator check: age 35, male coefficient, 90 kg, 180 cm and activity ×1.4 give resting energy 1,855 kcal/day, estimated maintenance 2,597, and a starting intake of 2,097 after the default 500 reduction. BMI is about 27.8, inside this tool’s reference scope. Changing the reduction to 300 gives 2,297. These are reproducible arithmetic examples, not measured outcomes or a forecast.
Suppose estimated maintenance is 2,400 kcal/day and a chosen target is 2,100 kcal/day. The planned gap is 300 kcal/day. These numbers illustrate the method; they are not a recommended reduction for every reader.
| Number in the example | Amount | Interpretation |
|---|---|---|
| Estimated maintenance | 2,400 kcal/day | Starting estimate of total energy use |
| Chosen intake target | 2,100 kcal/day | Planned daily food energy |
| Planned gap | 300 kcal/day | Difference between the estimate and target |
| Recorded intake today | 1,950 kcal | What a complete diary says was consumed |
| Remaining within the target | 150 kcal | Target minus recorded intake |
The planned gap is 300 kcal/day; the diary remainder is 150 kcal. They answer different questions.
The 150 kcal remainder is not the day's deficit. Comparing 1,950 with estimated maintenance gives a different estimated gap, 450 kcal. Both comparisons inherit the assumptions in the maintenance estimate and the completeness of the diary. Neither measures actual energy balance directly.
A calculator can multiply a daily gap into a weekly figure. That arithmetic does not establish a guaranteed weekly weight change. Avoid choosing an intake solely because it produces an appealing deadline on screen.
How fast should the plan try to move?
The CDC describes gradual loss of about 1–2 pounds per week as more likely to be maintained than faster loss. That is broad guidance, not a weekly result guaranteed by subtracting a fixed number of calories. It is not an instruction for every person to pursue the top of the range.
Use the pace guidance as context when inspecting the planner’s time frame. Then write down the proposed intake, intended activity and the foods and meals you would need to fit into an ordinary day. Ask whether the plan relies on skipping usual meals, an unrealistic activity increase or restriction you cannot sustain. A calorie total alone cannot establish nutrient adequacy; checking those practical constraints is a reason to revise the scenario, not proof that it is medically suitable.
When the planned intake does not fit, first compare a longer time frame or a revised goal with the same honest activity inputs. If you cannot find a workable option, bring the recorded scenario to a clinician or registered dietitian rather than selecting a larger reduction by trial and error.
NIDDK notes that energy needs can fall during weight loss. The starting estimate therefore may not describe the entire process. Review it as circumstances change instead of treating the first result as permanent.
How do you make the target usable day to day?
Translate the target into a record you can inspect. Include the foods and drinks actually consumed, their portions and the source of their figures. Keep uncertainty visible when an entry is an estimate. A target matched against incomplete entries can appear easier to meet than it really was.
For example, if lunch was recorded with an estimated portion, keep that limitation beside the lunch total. When you later learn the quantity, correct the entry. Do not compensate for a missing meal by lowering tomorrow's target; fix the record first.
IZeat is the five-star chef calorie tracker that suggests satisfying, great-tasting meals, so you enjoy every calorie you have left. After connection, tell the assistant the target and date you want to use, then describe what you ate. IZeat stores the target and meals and returns recorded totals. Your assistant can use those facts to discuss the remaining room or possible next meals. A dinner suggestion becomes a logged meal only after you identify what you actually ate.
IZeat does not store your body-weight trend or automatically award exercise calories. Keep progress observations separately and interpret them alongside the food record. For a full logging workflow, use the calorie-tracking pillar and calorie counting for weight loss.
What if the plan is not producing the expected change?
Check the evidence before making another cut. Is the maintenance estimate based on your current routine? Are the days complete? Are portion estimates being presented as measured quantities? Did an unrecorded meal or cooking ingredient change the comparison?
For a concrete review, keep a dated record with four fields: the target used, the day’s recorded intake and missing meals, changes in your activity, and body-weight observations kept separately. Compare observations taken consistently and look at their direction across the period, rather than treating one food total or weigh-in as a verdict. This page does not prescribe a universal number of days after which you must reduce intake.
If the evidence is incomplete, repair the diary or activity description before changing the target. There is no automatic conclusion that a stalled result means the target must be reduced. Health, medicines and other circumstances can also affect weight management; the CDC explicitly includes those factors in its guidance.
If the plan is difficult to follow, your progress is concerning or medical circumstances complicate the decision, discuss the target with a qualified professional. The useful next step may be changing the method or assumptions, rather than finding a stricter number.
Sources and method
Method: Mifflin–St Jeor resting energy × selected activity assumption gives estimated maintenance. For this weight-loss view, subtract the visible default 500 kcal/day reduction or the edited value. Adult overweight/obesity reference: NHLBI evidence review, 2013. The 750 kcal/day cap, BMI scope and lower-intake display boundaries are tool policies explained above. This is not the dynamic NIDDK model, a prescribed diet or a weight-loss forecast. Sources and method reviewed 4 October 2026; examples are arithmetic, not clinical validation.
- NIDDK Body Weight Planner.
- CDC: Steps for Losing Weight.
- NIDDK: Eating and Physical Activity.
- NIDDK: Planner scope.
Mifflin et al., 1990: resting-energy prediction. The equation underlies the local calculator; it is separate from the NIDDK goal planner.
Frequently asked questions
Short answers to the questions people type, each one sourced above.
Should I subtract 500 calories from whatever I eat now?
Not automatically. Current recorded intake may be above or below maintenance, and missing meals can make it look artificially low. The on-page calculator subtracts the visible reference reduction from estimated maintenance, not from your recorded intake. Review the resulting scenario; the external goal-and-time-frame planner is an optional comparison. A fixed subtraction does not become appropriate solely because it is easy to calculate.
Is 1,200 or 1,500 calories the right target for me?
Those familiar numbers are not a personalized answer. This page cannot prescribe an intake without your circumstances. A target that seems plausible for another person may not support your needs. Use individual guidance when a generic planning estimate is insufficient.
Should I eat back the calories from my workout?
First check whether usual exercise is already included in the maintenance estimate. Adding it again counts that assumption twice. IZeat does not automatically add exercise calories to your target; any adjustment is a separate planning decision, not a diary calculation.
Who should avoid using this as a self-directed weight-loss plan?
This is an adult planning explanation, not a plan for children, pregnancy or breastfeeding. Those circumstances need different guidance. If a health condition, treatment or problematic relationship with calorie restriction affects your situation, involve an appropriate qualified professional rather than relying on a generic target.