Calculator inputs
Estimate your daily direction
Use average data from ordinary days. Known maintenance calories override the modeled activity and exercise estimate.
Formula used
This calculator uses the Mifflin–St Jeor resting energy equation for adults. It then estimates daily energy use with your activity level. A supplied maintenance value replaces that estimate.
Male BMR = 10W + 6.25H − 5A + 5
TDEE = BMR × activity factor + additional exercise calories
Daily calorie balance = calorie intake − TDEE
Estimated daily body change (kg) = daily calorie balance ÷ 7,700
W is weight in kilograms. H is height in centimeters. A is age in years. The 7,700 kcal factor is a practical long-term approximation, not a daily biological rule.
How to use this calculator
- Use your current morning body weight in kilograms.
- Enter calories averaged across several typical days.
- Choose activity that reflects your usual week.
- Add exercise calories only when they are additional.
- Enter a known maintenance value only when it is reliable.
- Compare the result with seven-day average scale weights.
- Adjust slowly after at least two weeks of consistent data.
Example data
| Input or output | Example value | Meaning |
|---|---|---|
| Weight | 75 kg | Current morning weight |
| Average intake | 1,700 kcal/day | Average across normal eating days |
| Estimated energy use | About 1,987 kcal/day | Modeled daily expenditure |
| Daily balance | About −287 kcal/day | Estimated deficit |
| Weekly change | About −0.26 kg/week | Mathematical estimate before water changes |
Understanding Daily Weight Signals
Daily Weight Change Is An Estimate
This calculator translates calorie balance into a possible daily weight trend. It uses your intake and estimated energy needs. The result is not a promise. Bodies do not change in perfectly straight lines. Water, sodium, digestion, glycogen, sleep, and hormones can move scale weight quickly. Those shifts often hide real fat loss. Use daily results as context. Review weekly averages before changing your plan.
Calories, Energy Use, And Body Mass
Your body spends energy all day. Basal metabolism supports breathing, circulation, temperature control, and other essential work. Movement adds more energy use. Exercise and ordinary activity both matter. Together, these needs form total daily energy expenditure. When intake stays below expenditure, stored energy helps fill the gap. When intake stays above expenditure, body mass may rise over time. The calculator estimates this balance from your measurements and activity pattern.
Why The Scale Can Disagree
A calorie deficit may be present even when tomorrow’s scale is higher. A salty meal can increase water retention. A hard workout can cause temporary inflammation. More carbohydrates can refill glycogen stores. Each gram of glycogen holds water. Constipation and meal timing also affect the number. Menstrual cycles can create large short-term changes. These effects do not erase your calorie balance. They make daily scale readings noisy. Compare seven-day average weights instead. This approach shows the underlying direction more clearly.
Use Reliable Input Data
Enter average calories, not one unusually high or low day. Food weighing improves accuracy. Include drinks, oils, sauces, snacks, and tasting. Select an activity level that matches your normal week. Add exercise calories only when they are not already included. A known maintenance value can improve the estimate. It should come from several weeks of stable eating and stable average weight. Recheck estimates when your body weight or routine changes. Smaller bodies often need fewer calories over time. Consistent records improve results. Track food, weight averages, and activity patterns with care through several ordinary weeks.
Choose Sensible Adjustments
Large deficits can be difficult to maintain. They may reduce training quality, mood, recovery, and adherence. Moderate changes are easier to observe. Keep protein, fiber, fluids, and resistance training consistent. These habits can support fullness and muscle retention. Do not chase rapid changes after one weigh-in. Use the calculator alongside a repeated routine. Record morning weight after the bathroom, before food, under similar conditions. Then compare averages across at least two weeks.
When Extra Support Matters
Calorie tools cannot replace medical care. Speak with a qualified clinician for pregnancy, breastfeeding, eating-disorder history, diabetes, kidney disease, thyroid conditions, or medication-related weight changes. Seek help if eating feels distressing or compulsive. Young people need personalized guidance during growth. Athletes with demanding training also need individualized fueling. The safest goal is a sustainable pattern. Good progress includes energy, strength, sleep, and wellbeing, not only a scale number.
Frequently Asked Questions
Does this prove I am losing fat?
No. It estimates long-term energy balance. Daily scale changes also reflect water, digestion, glycogen, and measurement timing. Use several weeks of consistent average weights to judge the trend.
Why did my weight rise during a deficit?
Salt, carbohydrates, exercise soreness, bowel contents, and hormonal changes can temporarily increase scale weight. A single reading cannot confirm fat gain or fat loss.
Should I enter planned or actual calories?
Use actual calories averaged across recent normal days. Planned calories are useful for scenario testing, but they cannot confirm what you have consumed.
Why is activity level included?
Activity changes daily energy use. Choose the level that matches your typical work, walking, and routine. Do not choose a level based on one unusually active day.
Can I use a known maintenance value?
Yes. Use one supported by several weeks of stable food intake and stable average weight. When entered, it replaces the modeled energy-use calculation.
What does kg per day mean?
It is a mathematical energy-balance estimate. It does not mean the scale should change by that amount tomorrow. Daily body water can be much larger.
Why does the formula use 7,700 kcal?
It is a common long-term approximation for one kilogram of stored body energy. Real changes vary with tissue type, metabolism, adaptation, and time.
Is the metabolism estimate exact?
No. Resting metabolism equations use population averages. Your true energy use can differ. Compare the estimate with repeated body-weight trends and adjust cautiously.
How often should I update inputs?
Update body weight and calorie averages every one or two weeks. Revisit activity when your job, steps, training volume, or routine changes materially.
Should exercise calories be added?
Add them only when they are not already represented by your activity selection. Avoid double counting. Wearable calorie estimates can be uncertain.
Who should get professional advice?
Seek personalized guidance during pregnancy, breastfeeding, adolescence, recovery from an eating disorder, chronic disease, or medication-related weight changes. Consult a clinician for concerning symptoms.