Weight Loss Calculator
See how long it takes to reach your goal weight at a pace you choose, and the daily calorie deficit it takes to get there. Honest about how loss really works.
How the weight loss calculator works
Losing a kilogram of body fat takes roughly 7,700 calories of deficit, so a chosen weekly pace maps to a daily calorie shortfall. From the weight you want to lose, the tool estimates the weeks to your goal.
Choosing a safe pace
Most health agencies, including the CDC, suggest about 0.5 to 1 kg (1 to 2 pounds) per week as a safe, sustainable rate. Faster is tempting but harder to keep up and more likely to cost muscle, so a steady pace usually wins in the long run.
Why progress slows
This is a straight-line estimate, but real weight loss tapers. As you get lighter your body burns fewer calories, so the same deficit produces slower loss and plateaus are normal. Treat the date as a best case, and recalculate as your weight changes.
Frequently asked questions
How does the weight loss calculator work?
You enter your current weight, your goal weight, and a weekly pace. Using the rule that about 7,700 calories equals one kilogram of fat, the tool converts that pace into a daily calorie deficit and estimates how many weeks it will take to reach your goal.
How fast can I safely lose weight?
About 0.5 to 1 kg, or 1 to 2 pounds, per week is the range most health authorities consider safe and sustainable. Very aggressive deficits are harder to maintain and raise the risk of muscle loss, fatigue, and rebound, so steady usually beats fast.
Why is the timeline just an estimate?
Because weight loss is not perfectly linear. The 7,700-calories-per-kilogram figure is an average, and as you get lighter your body burns fewer calories, so the same diet yields slower loss over time. Water shifts and plateaus also blur the picture, so expect the real timeline to run a little longer.
How many calories should I eat to hit this deficit?
Find your maintenance calories first with the TDEE or calorie calculator, then subtract the daily deficit this tool shows. Eating that many calories should produce roughly the pace you picked, which you can adjust based on real results.
Should I eat below my BMR to lose faster?
No. Pushing intake below your basal metabolic rate for long is hard to sustain and can backfire. Base your target on your TDEE minus a moderate deficit, keep protein high, and add strength training to protect muscle while you lose.