How it’s calculated

To go = current weight − goal weight % of body weight = to go ÷ current weight × 100 Weeks at your pace = to go ÷ your recent change per week

Worked example: 220 lb now with a goal of 190 lb: 30 lb to go, and 30 ÷ 220 × 100 = 13.6% of your current weight. If you’ve averaged 1 lb a week lately, 30 ÷ 1 = 30 weeks — about seven months, at that pace.

The date is arithmetic, not a forecast. Pace usually changes over time and plateaus are common, so treat it as a rough marker and re-check it now and then. The calculator never suggests a rate — it only uses the one you enter.

Choosing a goal

A goal is personal. Some people choose a number on the scale, others a BMI range, a clothing size or simply how they feel day to day. Smaller steps — say, the next 5% of your starting weight — can be easier to picture than one big number.

If you use BMI as a reference, the BMI calculator shows the weight range that corresponds to 18.5–24.9 at your height. Your clinician can help you choose a goal that fits your health and history.

Keep track of the distance to your goal

Set your goal in GLPily and the weight screen shows a progress bar, how much is left and — once there’s enough data — an estimate of weeks to goal at your current pace. Free on iPhone and Android.

Free to download. Pro is an optional subscription for extras like the GLPily Grade for food and unlimited photo scans.

Frequently asked questions

How do I work out how much weight I have left to lose?

Subtract your goal from your current weight. To see it as a share of your body weight, divide that by your current weight and multiply by 100.

How long will it take to reach my goal weight?

No calculator can know that. This one only divides what’s left by the weekly pace you enter from your own records. If you don’t know your pace, the weight trend calculator can work it out from your weigh-ins.

What goal weight is right for me?

It depends on your health, history and what matters to you — worth deciding with your clinician. BMI ranges are one reference, but they don’t account for muscle, age or ethnicity.

Why does the calculator mention a BMI below 18.5?

If a goal falls in the underweight range at your height, we point it out so you can talk it through with a clinician.

Can I use it if I want to gain weight?

Yes. Enter a goal above your current weight and the calculator shows how much there is to gain.

Informational only, not medical advice. These calculators do simple arithmetic on the numbers you enter. They don’t diagnose anything and don’t replace your clinician or dietitian. Nothing you type is sent anywhere — it stays in your browser. Updated September 2026.

Goal weight calculator