Weight Loss Check-In Calculator
By Rick Campbell · Updated · Sourced to primary literature · Not medical advice
A logged deficit and a bathroom scale rarely agree on the same week. This page turns both into one comparison: expected kilograms from (estimated TDEE minus logged intake) times days, divided by 7,700, set beside the kilograms the scale actually moved.
The gap is not a verdict on your thyroid. Water, glycogen, weekend oils and a TDEE that was never measured all sit inside that difference. The result names an action this site will stand behind: hold the intake, relog food for a week, take a short diet break, or slow down if the drop is faster than 1% of starting weight a week.
Enter starting weight, today's weight, weeks on this intake, average daily calories, and the same vitals used for TDEE. You get expected versus actual change, weekly rates, and the next step, not a new crash target.
In brief
- Expected kg equals (TDEE minus intake) times days, divided by 7,700, the same planning constant as the rest of this site.
- A gap inside about 0.4 kg, or 25% of the expected change, is weekly noise. Hold the plan.
- If actual loss is under 40% of expected after six weeks, relog first, then consider a diet break at estimated maintenance.
- Faster than 1% of starting weight a week is outside what this site will plan. Raise intake toward the floor.
Calculator
What you'll see here
Expected kilograms from your logged intake, actual change, the gap, ranked causes, and a next action: hold, re-log, take a diet break, or slow down.
What the 7,700 line is actually claiming
Wishnofsky's 1958 note treated 3,500 kcal as the energy in one pound of body-weight change. Per kilogram that is about 7,700 kcal. Every weekly rate on this site uses that constant so the check-in, the time table and the deficit page speak the same language.
Hall and colleagues showed that a static 3,500 kcal per pound rule can predict about twice the annual loss a dynamic model does, because expenditure falls as mass falls. This calculator still uses the static line on purpose: it is a short-block forecast, not a twelve-month promise. The action rules exist because the line will drift.
If you treat the expected kilogram as a contract, you will cut again every time water hides a fortnight of fat. The useful question is whether the gap is noise, under-logging, or a cut that has run too long.
How expected kilograms are computed
Maintenance is Mifflin-St Jeor times the activity factor you pick, using today's weight. The daily gap is that TDEE minus the average intake you logged. Multiply by the number of days (weeks times seven) and divide by 7,700. That is expected fat-plus-water change on a static model.
Actual change is starting weight minus current weight. The gap is actual minus expected. Percent change is actual kilograms over starting weight. Weekly rates are those totals divided by the weeks you entered.
Activity is the usual miss. One level too high inflates TDEE by a few hundred kcal and makes the expected loss look larger than the body could have produced. If the gap is huge and the log looks honest, drop a level and run the form again.
Hold, relog, diet break, or slow down
Hold when the gap sits inside 0.4 kg or 25% of the expected change, whichever is larger. That band is smaller than a salty meal plus a hard training week. Changing the plan inside that band is how people yo-yo.
Relog when loss is slower than the line and you have fewer than six weeks on the intake. Oils, drinks, bites and weekends commonly add 200 to 400 kcal that never reach the log. Seven honest days beat a deeper cut.
A diet break (eat at estimated maintenance for 7 to 14 days) is offered when six or more weeks have produced less than 40% of the expected change. Slow down is reserved for a weekly drop faster than 1% of starting weight. That cap is the same rail as the deficit and time calculators.
Why water and glycogen look like a stall
A gram of glycogen binds about three grams of water. A higher-carb day, a hard week of lifting, or a menstrual cycle can add one to two kilograms without a gram of new fat. The 7,700 line does not know about that.
Use a seven-day average, not a single morning. Weigh after the same routine, after voiding, before food. If the average has not moved in two weeks and the waist is unchanged, then look at the log.
The weight-loss time calculator already warns that late weeks slip. This page is the fortnightly test of that warning. If both tools agree you are slow, the intake or the activity factor is the lever, not a new supplement.
Adaptive expenditure is real, and smaller than the internet
As weight falls, basal metabolism falls with it. Non-exercise movement often falls too. After a long cut, adaptive thermogenesis can shave a further few percent off TDEE. Hall's dynamic models put that in the maths. A four-week check-in will rarely need it.
This form only names adaptation after eight weeks of a large miss, and even then it is one cause among several. Most shortfalls at week four are unlogged food or a TDEE that was never yours.
A diet break does not 'reset' metabolism. It restores glycogen, raises daily movement for some people, and lets you practise maintenance. Then you resume the same deficit, not a deeper one.
What to do with the action
Hold means keep the same calories for another fortnight and walk the scale as a weekly average. Relog means weigh oils and pour drinks for seven days before you touch the target. A diet break means eat the TDEE on this result, then return. Slow down means raise intake toward 80% of TDEE or the sex floor.
Carry the same vitals into the deficit calculator if you change the target, and into the time calculator if you need weeks at a slower pace. Protein stays at the cutting tier on those pages.
Children and teenagers are out of scope. Adult energy maths does not run under 18 on this site.
How it's calculated
Expected change
Expected kg = (TDEE − intake) × (weeks × 7) ÷ 7,700
TDEE is Mifflin-St Jeor times the activity factor, using current weight. 7,700 kcal/kg is Wishnofsky's 3,500 kcal/lb in SI units.
Gap
Gap kg = (start kg − current kg) − expected kg
A gap inside 0.4 kg or 25% of expected change is treated as noise (hold).
Site maximum weekly rate
Max safe kg/week = start kg × 0.01
Faster than this, plus a small 0.05 kg buffer, triggers slow-down.
Worked example: 80 kg to 78.5 kg in 4 weeks at 1,800 kcal
- A 35-year-old man, 178 cm, 78.5 kg, sedentary: Mifflin BMR = 10×78.5 + 6.25×178 − 5×35 + 5 = 1,727.5 kcal.
- Sedentary TDEE = 1,727.5 × 1.2 = 2,073 kcal. Daily gap versus 1,800 kcal is 273 kcal.
- Expected change over 28 days = 273 × 28 ÷ 7,700 = 0.99 kg. Actual change = 80 − 78.5 = 1.5 kg.
- Gap = 1.5 − 0.99 = 0.51 kg, a little ahead of the line and inside a range water can explain.
- Weekly actual is 0.38 kg, under 1% of 80 kg (0.80 kg). Action is hold, not a deeper cut.
Where this number is used in the real world
- A fortnightly review when the scale has not matched the log.
- Deciding whether to hold calories or relog oils and weekends.
- Spotting a cut that is faster than 1% of starting weight a week.
- Choosing a 7 to 14 day diet break after six slow weeks.
- Handing the same vitals back to the deficit and time calculators.
Frequently asked questions
Why use 7,700 kcal per kilogram if Hall says it over-predicts?
The constant is a short-block planning line, not a year-long forecast. Wishnofsky's 3,500 kcal per pound is the same figure in other units, and every calorie tool on this site uses it so the pages agree. Hall's dynamic models show late months slip as expenditure falls. That is why this result offers hold, relog and diet-break instead of printing a new crash target from a single gap. Use the line for four to eight weeks, then re-estimate TDEE from current weight.
The scale went up this week. Should I cut more?
Not from one weigh-in. Glycogen, salt, a hard lifting week and the menstrual cycle can add one to two kilograms of water while fat is still falling. This form wants weeks on the same intake and a current weight that is a typical morning, not a Sunday after a restaurant. If the multi-week average is inside the hold band, keep the calories. If six weeks produced less than 40% of expected loss, relog food before you touch the target.
What does a diet break actually do?
You eat at the estimated TDEE on this page for 7 to 14 days, then resume the same deficit. It is not a metabolic reset and it does not unlock a new fat-burn mode. Glycogen and water return, training often feels better, and you practise the intake you will need to hold later. If weight climbs for three weeks and waist is up after you return to the deficit, the TDEE estimate was high and you re-check activity, not the idea of a break.
How honest does the calorie log need to be?
Honest enough that oils, sauces, drinks and weekend meals are weighed or poured, not guessed. Under-logging of 200 to 400 kcal a day is the common finding in free-living studies and it is enough to erase a planned 0.25 kg week. This page will tell you to relog before it tells you to eat less. If you cannot log for seven days, you do not have the data to deepen the cut.
Can I use a tracker TDEE instead of the form's estimate?
The form uses Mifflin-St Jeor times your activity pick so it matches the deficit and TDEE pages. A watch that adds session calories on top of an already active multiplier will double-count. If you have a four-week average intake that held weight stable, that observed maintenance is better than any equation. Put that number in as TDEE by choosing the activity level that lands nearest to it, then run the check-in.
When should I slow down even if I feel fine?
When weekly loss exceeds about 1% of the weight you started this block at. That is the fastest rate this engine will compute on the time and deficit pages, taken from common supervised-programme practice, not from a first home cut. Faster drops raise the share of lean mass you lose and make the later reverse harder. Raise intake toward 80% of TDEE or the 1,200 / 1,500 kcal floor and re-run the form in two weeks.
Keep going
A single number rarely tells the whole story. Alongside the check-in result, the weight-loss time calculator, the calorie deficit calculator, the energy in fat calculator and the TDEE calculator each add a different angle on the same measurements. For the reasoning behind the numbers, read Reading a weigh-in and Adaptation and plateaus.
Sources
- Hall KD, Sacks G, Chandramohan D, et al. Quantification of the effect of energy imbalance on bodyweight. Lancet 2011;378:826-37. doi.org/10.1016/S0140-6736(11)60812-X
- Wishnofsky M. Caloric equivalents of gained or lost weight. Am J Clin Nutr 1958;6:542-6. doi.org/10.1093/ajcn/6.5.542
- Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr 1990;51:241-7. doi.org/10.1093/ajcn/51.2.241
Cite this page
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- Campbell, R. (2026). Weight Loss Check-In Calculator. Body Stats. https://bodystats.co/app/weight-loss-check-in-calculator
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- “Weight Loss Check-In Calculator”, Body Stats, last updated 15 September 2026, https://bodystats.co/app/weight-loss-check-in-calculator
Every formula and threshold on this page is written out with its primary source on our methodology page. These results are informational and educational, not a diagnosis or a substitute for professional advice. See the medical disclaimer.
Last updated . Written by Rick Campbell; not medically reviewed. See review status.