Weight Loss Calculator
Enter your weight, the weight you want to reach and a date. The calculator gives you one number to eat each day, the weekly loss that buys, the date you actually arrive, and a safe pace band drawn around the plan.
Eat this much a day
2,006calories a day
5.0 kg to lose at about 0.5 kg a week. On this pace you reach 65.0 kg around Nov 13, 2026.
Week by week projection
- Safe pace, 0.25% to 1% of body weight a week
- Your plan
- Week 468.0 kgOct 2, 2026
- Week 766.5 kgOct 23, 2026
- Week 1065.0 kgNov 13, 2026
An estimate for healthy adults, not medical advice. Talk to a doctor before a deep deficit, and always if you are pregnant, breastfeeding, under 18 or managing a health condition.
How the number is worked out
The calculator starts from your maintenance calories, the amount you burn in a normal day. It uses the Mifflin-St Jeor equation for your resting burn, then multiplies by an activity factor between 1.2 for a desk job with no exercise and 1.9 for hard daily training. For a 34 year old woman at 85 kg and 165 cm who exercises three or four times a week, that comes to about 2,175 calories a day.
Next it works out how big a deficit your date needs. A kilogram of body fat holds roughly 7,700 calories, a pound about 3,500. Divide the calories you have to lose by the days until your date and you get the daily deficit. Your daily target is maintenance minus that deficit. If the woman above wants to reach 75 kg in 15 weeks, she needs 77,000 calories of deficit over 105 days, about 730 a day, so she eats around 1,425.
Last comes the safety check. Loss is judged against a band of 0.25 to 1 percent of body weight per week, and the daily target never drops below 1,200 calories for women or 1,500 for men. If your date would need a target under that floor, the calculator holds you at the floor and shows the earliest date that pace can reach your goal instead. Her plan loses 0.68 kg a week, 0.8 percent of her body weight, so it stays inside the band.
How many calories to lose weight
For most adults the answer is maintenance minus 300 to 750 calories, and never more than a quarter of maintenance. On a 2,500 calorie maintenance that means eating 1,875 to 2,200. A bigger deficit does not speed things up for long. Hunger climbs, training suffers, and more of the loss comes from muscle.
Recalculate after every 4 to 5 kg. A lighter body burns fewer calories at rest and during movement, so a target that worked at the start of a plan turns into maintenance halfway through. The calculator remembers your inputs, so updating means changing one field.
Losing 5 kg in a month
Five kilos in 30 days needs about 1,280 calories of deficit every day. For most people that lands under the floor, which is why the calculator will move your date instead. Real fat loss for a 70 kg person tops out near 0.7 kg a week, so 2.5 to 3 kg a month is the honest ceiling. The scale often shows more in the first week because water drops when you cut carbs and sodium, and that part comes back.
Losing 30 pounds in 3 months
Thirty pounds in 13 weeks is 2.3 pounds a week, roughly 1,200 calories of deficit a day. At 260 pounds that is under 1 percent of body weight and the calculator lets it through. At 180 pounds it is over the band, and the projected date moves out to about five months. Both plans work. The second one just has a later finish.
Track it in NutriScan
A daily target only helps if you can see what you ate against it. NutriScan logs a meal from a photo, your voice, a barcode or a typed line, then shows calories and macros against the number you set here. The home screen tells you where the day stands before dinner, which is when the decision still matters.
The free plan gives you 5 photo scans a week plus unlimited manual logging, water tracking and the fasting timer. Premium removes the scan cap and costs about $59 a year.
Frequently asked questions
How many calories should I eat a day to lose weight?
Take your maintenance calories and subtract a deficit. A 500 calorie daily deficit works out to roughly 0.45 kg or 1 pound a week, because a kilogram of body fat holds about 7,700 calories. For most adults the answer lands between 1,400 and 2,200 calories a day, which is why the number has to come from your own weight, height, age and activity level rather than a chart.
Is losing 5 kg in a month safe?
It depends on your starting weight. Safe loss runs at 0.25 to 1 percent of body weight a week, so 5 kg in a month is inside the band at 125 kg and well outside it at 70 kg. The calculator checks your own numbers against that band and moves the finish date instead of dropping you below the calorie floor.
How long does it take to lose 30 pounds?
At 1 pound a week it takes about 30 weeks, at 1.5 pounds a week about 20 weeks. Three months is possible only for someone heavy enough that 2.5 pounds a week still sits under 1 percent of body weight, which means a starting weight over 250 pounds. Enter your numbers and the projection shows the real date.
Why does the calculator say my target date is not safe?
Because hitting it would need a daily target below the floor of 1,200 calories for women or 1,500 for men. Under that, hitting your vitamin and protein needs gets hard and more of the loss comes from muscle. The calculator holds you at the floor and shows the earliest date that pace can reach your goal.
Do I have to hit the calorie number exactly every day?
No. Your body works on a weekly average, so a day 300 over and a day 300 under cancel out. Aim to land within about 100 calories most days and judge progress on a weekly average weight rather than any single morning, since water shifts of 1 to 2 kg are normal.
Related calculators
Your inputs are saved between these pages, so each one opens with your numbers filled in.
- TDEE calculator for maintenance calories at every activity level
- Weight gain calculator for the surplus and timeline of a lean bulk
- Protein intake calculator for daily grams and a per-meal split
- Calories burned calculator for one workout or a day of steps
- NutriScan for weight loss for how the app handles a deficit day to day