Build your estimate
Use adult values. Choose a sustainable target and review results regularly.
Formula used
Body mass index: BMI = weight in kilograms ÷ height in meters².
Resting energy: female reference = 10W + 6.25H − 5A − 161. Male reference = 10W + 6.25H − 5A + 5.
Maintenance calories: estimated resting energy × activity factor.
Daily deficit: weekly target in kilograms × 7,700 ÷ 7. Planning calories = maintenance calories − daily deficit.
How to use this calculator
- Select the calculation reference used for the resting energy estimate.
- Enter your adult age, height, current weight, and goal weight.
- Choose your usual activity level, not your best possible week.
- Select a weekly loss target that feels steady and realistic.
- Review the BMI, calorie estimates, milestones, and projected date.
- Use weekly trends, not single weigh-ins, before changing the plan.
Example planning snapshot
| Input | Example value | Why it matters |
|---|---|---|
| Current weight | 110 kg | Sets BMI and energy estimates. |
| Goal weight | 85 kg | Shows total planned weight change. |
| Activity | Moderately active | Adjusts estimated maintenance calories. |
| Weekly target | 0.50 kg | Creates the daily planning deficit. |
Build a sustainable weight-loss plan
Weight loss becomes easier when the plan feels clear and measurable. A calculator can turn broad goals into useful daily numbers. It estimates your body mass index, maintenance calories, target intake, and likely timeline. These values are planning tools, not medical diagnoses. Review your numbers regularly. Use them to guide small adjustments rather than demanding perfect results.
A realistic goal protects energy, confidence, and long term consistency. Fast plans can look exciting, yet they often feel difficult to maintain. A moderate weekly target usually creates a smaller daily calorie gap. Choose a goal weight that supports your health, strength, movement, and lifestyle. Avoid comparing your path with someone else's timeline.
Body mass index gives one general weight to height reference. Use it beside other signals. Notice your waist measurement, fitness level, blood pressure, energy, and laboratory results when available. Athletes and muscular people may see a higher index without carrying excess fat. A qualified clinician can help interpret confusing results.
Calorie estimates begin with your resting energy needs. The calculator uses age, height, body weight, and sex selection to estimate basal metabolic rate. It then applies an activity multiplier. This produces an estimated maintenance level. A selected weekly loss rate creates a daily deficit estimate. The suggested calorie target equals maintenance calories minus that deficit. The page flags targets that fall below general calorie floors. These checks are not personalized treatment plans.
Food quality matters even when calories are controlled. Build meals around vegetables, fruit, beans, whole grains, lean proteins, and healthy fats. Protein may support fullness and help protect lean tissue during weight loss. Fiber can improve satisfaction and regularity. Drink water often. Limit liquid calories when possible. Plan favorite foods intentionally. A flexible pattern is usually easier to continue than strict rules.
Movement can help, but you do not need extreme exercise. Start with activity that fits your current ability. Walking, cycling, swimming, resistance training, and home routines can all help. Strength work is valuable because it supports muscles during a calorie deficit. Increase activity slowly. Rest when needed. Seek professional guidance before starting a demanding program, especially with heart, joint, metabolic, or mobility concerns.
Track more than the scale. Daily weight can move because of water, sodium, hormones, digestion, and training. Compare weekly averages or repeat measurements under similar conditions. Celebrate actions as well as outcomes. Prepare meals, log honestly, sleep consistently, and move often. When progress stalls, review portions, habits, and activity before making large changes. Small corrections are easier to maintain. Keep records that reveal trends over time.
The strongest plan is one you can repeat. Use the calculator as a starting point. Set one or two practical habits for the next week. Recalculate after meaningful weight changes. Speak with a registered dietitian or healthcare professional when you need individualized advice. Your goal is not perfection. Your goal is steady progress that fits real life.
Frequently asked questions
What does this calculator estimate?
It estimates BMI, basal metabolic rate, maintenance calories, a calorie target, total weight change, and a projected timeline. Every output is an estimate. Food intake, activity, sleep, medications, and changing body weight can move the real result.
Is this calculator a medical assessment?
No. It provides general adult planning estimates. It cannot diagnose health conditions or replace individualized guidance. Speak with a qualified healthcare professional when you have medical conditions, take medications, are pregnant, nursing, under eighteen, or have a history of disordered eating.
How is body mass index calculated?
BMI equals weight in kilograms divided by height in meters squared. It is a broad screening measure. It does not directly show body fat, muscle mass, bone structure, pregnancy status, or where body fat is stored.
What weekly loss target should I select?
Many adults choose a gradual target such as 0.25 to 0.75 kilograms weekly. A faster setting creates a larger estimated deficit. Choose a pace you can sustain, and seek individualized advice before pursuing aggressive changes.
Why is my calorie target lower than expected?
The calculation subtracts the estimated daily energy deficit required by your selected weekly target from maintenance calories. A lower activity setting or faster target will reduce the number. The calculator displays a general calorie floor warning when the estimate becomes very low.
Why does the target date change?
The date is based on your current weight difference and selected weekly rate. Real weight loss is rarely perfectly linear. Water balance, adherence, activity, and metabolic adaptation can change the pace. Treat the projected date as a flexible milestone.
Should I add strength training?
Strength training can support muscles and physical function during weight loss. Start at an appropriate level and progress gradually. Walking and other aerobic activity can also help. Choose activities you can perform safely and consistently.
Can I eat more than the estimated target?
Yes, the number is a planning estimate rather than a strict rule. A smaller deficit may produce slower loss and can be easier to maintain. Prioritize adequate nutrition, recovery, and consistency instead of chasing the lowest possible intake.
How often should I recalculate?
Recalculate after a meaningful weight change, a major activity change, or every four to six weeks. Maintenance calories usually decrease as body weight decreases. Updating the plan keeps targets closer to your current situation.
What should I do during a plateau?
First, review weekly average weight instead of one daily reading. Check portions, drinks, snacks, activity, sleep, and tracking accuracy. Make one small change at a time. Seek professional support when the plateau is prolonged or concerning.
Can I use this while managing a health condition?
Use it only as a discussion starter. Diabetes, kidney disease, heart disease, endocrine conditions, injuries, and some medicines can change safe nutrition or activity needs. Ask your clinician or dietitian for an individualized plan.