When will I reach my goal weight?

When could you reach your goal?

UnitsMetric (kg, cm)US (lb, ft, in)Your weight nowYour goalYour paceSteady, as the app plansGentleFaster

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How the calculator works

It divides the weight you'd like to lose by a weekly pace and counts the weeks from today. The pace Fasting Tracker plans with is half a kilo (about 1.1 lb) a week, or 0.7% of your body weight a week if that's less, which is the case below about 71 kg (157 lb). Losing 8 kg from 80 kg at that pace takes about 16 weeks. If your goal is to gain weight, it plans a quarter of a kilo a week. Nothing you enter leaves your browser.

That pace sits at the gentle end of public health advice: people who lose weight gradually and steadily, about 1 to 2 pounds (roughly 0.5 to 1 kg) a week, are more likely to keep it off ¹.

Weekly pace	5 kg (11 lb)	10 kg (22 lb)
0.25 kg (about 0.5 lb)	20 weeks	40 weeks
0.5 kg (about 1.1 lb), Fasting Tracker's plan	10 weeks	20 weeks
0.75 kg (about 1.7 lb)	About 7 weeks	About 13 weeks

Why real progress slows down

A steady line is a simplification. As you lose weight, your body needs less energy, so the gap between what you eat and what you burn shrinks. Researchers at the US National Institutes of Health modelled this and found that weight responds slowly to a change in eating, with half of the eventual change taking about a year ². Weight also moves up and down from day to day with water and food. A slower month is the expected shape of the curve, not a failure: see weight loss plateaus.

Fasting itself works mainly by helping you eat less. In a year-long trial, an 8-hour eating window plus a calorie target led to about the same weight loss as the calorie target alone ³. Losing faster than you need to also makes it harder to keep muscle, so keep your protein up ⁴.

Your own pace, in Fasting Tracker

This calculator assumes a pace. Fasting Tracker uses yours: it draws a trend line through your weigh-ins, so one heavy morning doesn't count, and shows the date you could reach your goal if the trend keeps going. It only shows a date when your trend is clearly heading towards your goal and it's within two years, and it counts a goal as reached when the scale shows it two days in a row or the trend gets there. It won't let you set a goal below a healthy BMI for your height (check yours).

Every date here is arithmetic, not a promise. Bodies differ, and life happens. Use the date to plan, then let your trend tell you how it's really going.

Sources

1. Centers for Disease Control and Prevention. Steps for Losing Weight. 2025. www.cdc.gov/healthy-weight-growth/losing-weight/index.html
2. Hall KD, Sacks G, Chandramohan D, et al. Quantification of the effect of energy imbalance on bodyweight. Lancet. 2011;378(9793):826-37. doi.org/10.1016/S0140-6736(11)60812-X
3. Liu D, Huang Y, Huang C, et al. Calorie Restriction with or without Time-Restricted Eating in Weight Loss. N Engl J Med. 2022;386(16):1495-1504. doi.org/10.1056/NEJMoa2114833
4. Leidy HJ, Clifton PM, Astrup A, et al. The role of protein in weight loss and maintenance. Am J Clin Nutr. 2015;101(6):1320S-1329S. doi.org/10.3945/ajcn.114.084038
5. Grajower MM, Horne BD. Clinical Management of Intermittent Fasting in Patients with Diabetes Mellitus. Nutrients. 2019;11(4):873. doi.org/10.3390/nu11040873