Free Macro Calculator
The macro calculator that shows its work.
Every calorie, macro, and adjustment cites the peer-reviewed study behind it. No guesswork, no 1919 formulas, no marketing math. Takes about 90 seconds.
- Mifflin-St Jeor + Katch-McArdle
- Modernized activity multipliers
- Every number cites its source
Let's start with the basics.
These inputs feed the BMR equation.
BMR equations were validated on biological-sex baselines. Trans and non-binary users: pick whichever produces the more accurate estimate for your current hormonal profile.
Why this calculator is different
We use modern activity multipliers
Most calculators still use the 1.2 / 1.375 / 1.55 / 1.725 / 1.9 activity ladder derived from a 1919 Carnegie Institution study of 239 lean, active young adults. A 2024 Scientific Reports validation against doubly-labelled-water found only 43% of individuals land within 10% of predicted TDEE using the classic multipliers. We use ranges informed by the FAO/WHO/UNU 2004 Physical Activity Level consultation.
Katch-McArdle unlocks when you know your body-fat percentage
For lean or trained individuals, BMR predictions based on lean body mass (Katch-McArdle, Cunningham) consistently outperform weight-only equations. If you have a body-fat percentage from a DEXA, BIA, or callipers, we use it.
Protein anchored to Morton 2018 and ISSN 2017
We set protein first (goal-adjusted, LBM-anchored when possible), then fat with a hormone-safe floor, then carbs fill the remainder. Not backwards like calculators that default to AMDR percentages.
Safety guardrails, not just a disclaimer footer
We refuse to serve a plan to anyone under 18, and route pregnant/breastfeeding users and those with BMI extremes to a physician or registered dietitian. Every cutting protocol has a hard-coded minimum calorie floor.
Frequently asked questions
›Is the Scinergy macro calculator free?
Yes, the macro calculator is 100% free. No account is required to see your results. You can optionally submit your email to get the plan sent to you.
›What equation does the calculator use for BMR?
We use Mifflin-St Jeor by default because a large 2005 meta-analysis found it the most accurate general-population equation. If you provide a body-fat percentage (from DEXA, BIA, or callipers), we switch to Katch-McArdle, which is more accurate for lean or trained individuals.
›Why do your activity multipliers differ from other calculators?
Most calculators still use the 1.2, 1.375, 1.55, 1.725, 1.9 activity ladder derived from a 1919 Carnegie study of 239 lean, active young adults. A 2024 Scientific Reports validation against doubly-labelled water found only 43% of individuals land within 10% of predicted TDEE using those classic multipliers. We use ranges informed by the FAO/WHO/UNU 2004 Physical Activity Level consultation.
›Does the calculator work for women in perimenopause or postmenopause?
Yes. Female users can optionally indicate menstrual status (regular, irregular, perimenopause, postmenopause). Peri- and postmenopausal women get a higher absolute-protein anchor (2.2 g/kg body weight ceiling), a higher per-meal protein floor (30 g), a shorter post-workout protein window (60 minutes), and a higher fiber floor (28 g/day), based on the Sims / Haver / Colenso-Semple synthesis.
›How much protein should I eat per day?
For fat loss or muscle gain, evidence supports 1.6 to 2.2 g of protein per kg of body weight per day (Morton 2018 meta-analysis, ISSN 2017 position stand). Older adults and peri/postmenopausal women benefit from the upper end. We calculate an exact target based on your body composition and goal.
›Do you set fat or protein first?
We set protein first, then fat with a hormone-safe floor (0.6 g/kg minimum), then carbs fill the remainder. This is the opposite of most calculators, which default to AMDR percentages and can leave protein or fat too low for hormone health.
›Is a calorie deficit safe?
Yes, when it's kept moderate. We cap cutting protocols at a hard-coded minimum calorie floor, refuse to serve plans to users under 18, and route pregnant, breastfeeding, or BMI-extreme users to a physician or registered dietitian.