Best protein calculators for GLP-1 diets in 2026

If you're on Ozempic, Wegovy, Mounjaro, Zepbound, or retatrutide and eating less overall, the number that matters most isn't calories — it's grams of protein per day, and most calorie-tracking apps still default to a target built for someone who isn't losing appetite on purpose. This guide ranks the tools that actually help GLP-1 users hit a protein number in 2026, including one honest look at where a weight-loss calculator fits into that picture and where it doesn't.

Why protein tracking matters on GLP-1 medications

Appetite suppression is the whole mechanism — that's also the problem. When total intake drops, protein intake drops with it unless you deliberately track it, and lean mass loss shows up in the trial data, not just anecdotes. Sub-studies of trials such as STEP-1 (semaglutide) have reported lean mass making up roughly a third of total weight lost, which is why obesity medicine guidance leans on a bodyweight-scaled protein range rather than a flat number.

The GLP1 Weight Loss Calculator projects your week-by-week weight using clinical trial data from studies like STEP-1 and SURMOUNT-1, which gives you the exact input a protein formula needs — your projected bodyweight at week 12, week 24, or wherever you are in your titration schedule. It's not a protein calculator on its own, and this guide treats it accordingly.

The best GLP-1 protein calculators for 2026 (ranked)

Best overall: pairing a manual bodyweight formula with the GLP1 Weight Loss Calculator's weight projections. Best for micronutrient tracking: Cronometer. Best for simple daily logging: MyFitnessPal.

What makes the best GLP-1 protein calculator

• Scales the protein number to bodyweight instead of using one flat daily figure
• Uses a range grounded in obesity-medicine or bariatric guidance (1.2-1.6 g/kg), not the general 0.8 g/kg RDA built for sedentary adults
• Recalculates as weight drops instead of freezing the target at week one
• Lets you log actual food against the target, not just generate a number once
• Costs nothing to access the core feature, since most GLP-1 users are already paying for the medication

At a glance

Tool	Best for	Standout feature	Key limitation
GLP1 Weight Loss Calculator	Pairing weight timeline with protein target	Trial-based weight projections (STEP-1, SURMOUNT-1)	Doesn't calculate protein grams itself
Manual bodyweight formula	A fast, clinically grounded number	1.2-1.6 g/kg range, no app needed	No logging or reminders
Cronometer	Micronutrient + protein tracking	Detailed nutrient database	Denser interface than casual calorie apps
MyFitnessPal	Simple daily food logging	Large food database, quick habit	Default protein target isn't GLP-1 specific
Lose It!	Goal-based coaching with macros	Ties weight goals to daily protein budget	Nutrient detail thinner than Cronometer

1. GLP1 Weight Loss Calculator: best for pairing your weight-loss timeline with a protein target

The GLP1 Weight Loss Calculator projects week-by-week weight loss on Ozempic, Wegovy, Mounjaro, Zepbound, or retatrutide using clinical trial data rather than a generic BMI formula. That projected bodyweight number is exactly what a protein formula needs at any point in your titration schedule, whether you're at week 4 or month 6 — see how those averages break down in how much weight people lose on Ozempic by month.

GLP1 Weight Loss Calculator pros:

• Free, no login required
• Projections tied to named trials instead of a generic estimate
• Updates as you move through your titration schedule

GLP1 Weight Loss Calculator cons:

• Doesn't output a protein gram target on its own
• No food logging feature — it's a projection tool, not a tracker

Best for: GLP-1 users who want a clinically grounded weight number to plug into the formula in pick #2. Verdict: Use it for the weight input, not as a standalone protein calculator.

2. Manual bodyweight protein calculator: best for a fast, clinically grounded number

Multiply your current or projected bodyweight in kilograms by 1.2 to 1.6 to get a daily protein gram target — this is the range commonly cited in obesity-medicine and bariatric-clinic guidance for people losing weight quickly, including on GLP-1 medications. A 90 kg starting point lands between 108 and 144 grams per day; at 75 kg after several months, that range drops to 90-120 grams.

Manual formula pros:

• Takes under a minute, no app or account
• Free and adjusts instantly as your weight changes
• Matches the clinical range rather than a general fitness default

Manual formula cons:

• No logging feature to track whether you actually hit the number
• Requires you to remember to recalculate every few weeks

Best for: anyone who wants a real number today without installing anything. Verdict: Use — this is the fastest legitimate option on the list.

3. Cronometer: best for tracking protein alongside micronutrients

Cronometer is a nutrient-tracking app that lets you set a custom daily protein gram target and logs it against a detailed food database, including micronutrients like iron, B12, and fiber that also tend to drop when appetite falls on a GLP-1 medication.

Cronometer pros:

• Custom protein targets, not locked to a generic default
• Detailed micronutrient view, useful when overall intake is low
• Verified food database reduces logging guesswork

Cronometer cons:

• Denser interface than a simple calorie counter
• More detail than some users need if protein is the only concern

Best for: people also worried about vitamin and mineral intake dropping alongside appetite. Verdict: Use it if micronutrient visibility matters to you, not just protein.

4. MyFitnessPal: best for simple daily food logging

MyFitnessPal is a widely used food-logging app with a barcode scanner and macro targets, including a protein progress bar you can adjust manually once you know your gram target from the formula above.

MyFitnessPal pros:

• Large food database speeds up logging
• Easy habit to keep for daily tracking
• Simple visual progress bar for protein

MyFitnessPal cons:

• Default protein target is built for general fitness goals, not GLP-1 lean-mass preservation — you have to override it manually
• Deeper nutrient detail sits behind extra taps

Best for: someone who wants a low-friction daily logging habit over clinical precision. Verdict: Use it, but reset the default protein target yourself first.

5. Lose It!: best for goal-based coaching tied to protein

Lose It! is a food and weight logging app that ties daily macro budgets, including protein, to a stated weight goal, which can work well if you want your weight target and protein target managed in one place.

Lose It! pros:

• Goal-based structure links weight and protein in one view
• Straightforward setup for daily logging

Lose It! cons:

• Nutrient database is less detailed than Cronometer for micronutrients
• Not built specifically around GLP-1 lean-mass concerns

Best for: people who want weight and protein goals bundled into one app rather than tracked separately. Verdict: Optional — redundant if you already use MyFitnessPal or Cronometer.

How we ranked

Each tool was judged against the criteria above: whether the protein number scales to bodyweight, whether it's grounded in a clinical range instead of the general 0.8 g/kg RDA, whether it recalculates as weight drops, whether it lets you log real intake, and whether the core feature is free. The manual formula and GLP1 Weight Loss Calculator score highest on clinical grounding; Cronometer and MyFitnessPal score highest on logging.

Which protein calculator should you choose?

If you only do one thing, run the manual bodyweight formula (1.2-1.6 g/kg) using your current weight, and recheck it every time you drop another 5-10 pounds. Pull your projected weight at future weeks from the GLP1 Weight Loss Calculator so the formula stays accurate as you move through 2026, then log actual intake in Cronometer if micronutrients concern you or MyFitnessPal if you just want a simple daily habit. Skip Lose It! unless you specifically want weight and protein goals bundled in one screen.

FAQ

One last thing

Most people set their protein target once, at week one, and never touch it again — that's the single biggest gap in this whole category. Set a recurring reminder to rerun the formula every 5-10 pounds instead of trusting a number you calculated three months and thirty pounds ago.

Related guides

• How much weight you lose on Ozempic by month
• Project your own week-by-week weight loss timeline