GLP-1 Cost per Pound Calculator for Zepbound, Wegovy and Ozempic

1. Choose "I’ve started", "I’m deciding" or "I’m at goal", and your currency.
2. If you have started, enter what you spend (per month or in total), the date you started, your starting weight and your weight today, and your medicine and dose. Add what you no longer spend on food to see the cost net of it.
3. Read what each pound, kilogram or stone has cost so far and what the next three months' loss is likely to cost on the trial curve at your month.
4. If you are deciding, enter your weight and up to three options with their monthly price to see them ranked by cost per expected pound over 12 months. At goal, the calculator shows what the spend is keeping off and what a longer gap between doses would cost a month.

The page lists no drug prices. What you pay depends on your insurance, pharmacy, dose, the pen, vial or KwikPen you get and any savings program, so the calculator takes your own figure.

Cost per pound = monthly cost ÷ monthly loss. The 12-month spend is the monthly cost × 12, and the 12-month loss is the monthly loss × 12.

With $400 and 8 lb a month: $400 ÷ 8 lb = $50 per pound, $400 × 12 = $4,800 a year, and 8 × 12 = 96 lb a year.

The 12-month loss assumes the pace never slows. From a 220 lb start, 96 lb is 43.6% of body weight: more than twice the 20.9% mean on tirzepatide 15 mg in SURMOUNT-1, which took 72 weeks (Jastreboff et al., NEJM 2022).

The table spreads each trial arm’s mean loss evenly over the trial, from a 220 lb start (SURMOUNT-1; STEP 1). A month here is 30.44 days (365.25 ÷ 12), so 68 weeks is 15.6 months and 72 weeks is 16.6 months.

For the first row: 220 × 0.149 = 32.8 lb, and 32.8 ÷ 15.6 = 2.1 lb a month. The rows come from two trials in different people. The one direct comparison, SURMOUNT-5, gave 20.2% on tirzepatide and 13.7% on semaglutide at 72 weeks in 751 adults, each on the highest dose they tolerated (Aronne et al., NEJM 2025).

Ozempic is approved for type 2 diabetes, and its label stops at 2 mg a week (Ozempic prescribing information, section 2.2). People with type 2 diabetes lose less, even on a higher dose: semaglutide 2.4 mg, above the Ozempic ceiling, gave 9.6% at 68 weeks in that group (Wegovy prescribing information, Table 8, Study 3). That is 220 × 0.096 ÷ 15.6 = 1.4 lb a month, so the same spend buys fewer pounds.

In STEP 4, semaglutide 2.4 mg took off 10.6% in a 20-week run-in and a further 7.9% over the next 48 weeks (Rubino et al., JAMA 2021). The same monthly spend therefore buys fewer pounds as treatment goes on.

The table applies those STEP 4 figures to a 220 lb start at $400 a month.

The arithmetic: 220 × 0.106 = 23.3 lb, leaving 196.7 lb; 196.7 × 0.079 = 15.5 lb. Over the whole 68 weeks, $400 × 15.6 = $6,240, and $6,240 ÷ 38.8 lb = $161 per pound. The run-in figure counts only the 803 people who reached 2.4 mg by week 20 and went on to randomization.

Divide everything you have spent since your first dose by everything you have lost since then. That one ratio takes in the fast months and the slow ones, so it does not depend on which month you pick.

The calculator does this division for you: enter what you have spent in total, or per month with the date you started, and your weight then and now. The result is your cost per pound to date. Weight logging is free in Pensday, and its chart gives the total loss since you started.

Count what leaves your account each month for the prescription:

• the medication itself, after insurance or any savings card
• a recurring prescription, telehealth or membership fee, if you pay one
• syringes, needles and sharps disposal, if you buy them separately
• delivery or shipping charges

Zepbound comes in single-dose pens, single-dose vials, multi-dose vials and KwikPens (Zepbound prescribing information, section 3), and your cost can depend on which one you are prescribed. How many mL are in a Zepbound vial compares the vial and KwikPen formats, including Lilly’s self-pay listing. If you pay for a tracker app, add it too; GLP‑1 tracker app cost lists the subscription prices.

Once you reach a stable weight, your monthly loss is close to zero and the division has no useful answer. The calculator then shows what the spend is keeping off instead of a cost per pound.

The spend is then paying to keep the weight off. SURMOUNT-4 (Study 4 in the Zepbound label) moved half of the people who finished a 36-week lead-in to placebo. By week 88 they had gained 14.0%, while those who stayed on Zepbound lost a further 5.5% (Zepbound prescribing information, section 14). More on regain is in what happens after you stop, and the GLP‑1 weight loss calculator turns the trial averages into a 12-month loss for your own starting weight.