Loading page
About this tool
Net carb allowance, protein and fat targets for each Atkins phase — Induction, Balancing, Fine-Tuning and Lifetime Maintenance.
The Atkins Phase Macro Calculator turns the four published Atkins phases into a daily macro target: the net carb allowance fixed by your phase, a moderate protein amount set per kilogram of body weight, and dietary fat filling the remaining calories. Energy needs come from the Mifflin-St Jeor equation multiplied by an activity factor, so the numbers move with your size and training load rather than a one-size-fits-all template. It is built for anyone running Atkins 20 or Atkins 40 who wants to know exactly how many net carbs today allows and what the rest of the plate should look like.
Open Atkins Phase Macro Calculator on AltFTool — it loads instantly in your browser.
Enter Sex (for the BMR equation), Age (years), Weight (kg) and Height (cm), then pick an Activity level from 'Sedentary (desk job, little exercise)' to 'Athlete (twice-daily or physical job)'.
Choose the Atkins phase — Phase 1 Induction through Phase 4 Lifetime Maintenance — plus 'Week number in this phase' (or 'Your carb tolerance (g net carbs/day)' in maintenance), a Goal, and Protein (g per kg body weight).
Read the Daily net carb allowance with the fat / protein / carb calorie split bar and the Atkins carb ladder table; a warning appears if fat falls under 20% of calories. Press 'Copy result' to save it.
Applies the real 20 g / +5 g / +10 g weekly steps instead of a single fixed number.
Fat grams are whatever is left after carbs and protein hit your calorie target.
Warns when fat drops under 20% of calories, which usually means protein is set too high.
20 g of net carbs a day, held for a minimum of two weeks. Atkins asks that 12–15 g of that 20 come from foundation vegetables such as spinach, broccoli, cauliflower and salad leaves, leaving only about 5–8 g for everything else.
Net carbs are total carbohydrate minus fibre minus sugar alcohols. Fibre and most polyols are not absorbed as glucose, so they have little effect on blood sugar — that is why a 100 g serving of broccoli with 7 g total carbs and 3 g fibre counts as 4 g net carbs.
Phase 2 starts at 25 g and adds 5 g a day each week while weight loss continues, up to about 50 g. Phase 3 starts at 50 g and adds 10 g a week up to roughly 80 g. If the scale stalls, you drop back to the previous week's number rather than pushing higher.
Atkins is moderate-protein, not high-protein — commonly 1.2–1.6 g per kilogram of body weight, which for a 90 kg person is roughly 110–145 g a day. Going much higher squeezes fat out of the plan and makes the calorie target very hard to eat. Anyone with reduced kidney function should agree a protein level with their doctor first.
Add the Atkins Phase Macro Calculator widget to your blog or website — free, responsive, no signup. Just keep the “Widget by AltFTool” credit link visible.
<iframe src="https://www.altftool.com/embed/widget/atkins-phase-macro-calculator"
title="Atkins Phase Macro Calculator — free AltFTool widget"
width="100%" height="640" style="border:0;border-radius:12px;overflow:hidden"
loading="lazy" referrerpolicy="no-referrer-when-downgrade" allow="clipboard-write"></iframe>
<p style="font-size:12px;margin:4px 0 0">Widget by <a href="https://www.altftool.com/tools/all/atkins-phase-macro-calculator?utm_source=embed&utm_medium=widget" rel="nofollow">AltFTool — free online tools</a></p>