Nutrition calculator
Zigzag calorie calculator
Plan a week where the average holds your target but no two days look the same — big training days, quiet rest days, and a Saturday you can actually eat through. Edit the grid, watch the weekly average and the projected weight change move. Free, instant, no sign-up.
Maintenance is what you burn on an average day — your TDEE. The target average is what you want the week to come out at.
Your week, day by day
The weight projection uses the 7,700 kcal ≈ 1 kg approximation (3,500 kcal ≈ 1 lb). It is a planning heuristic, not a law: it assumes every calorie of the balance comes out of fat and that maintenance stays put as you get lighter. Neither is quite true, so expect the real number to lag the projection over a long diet.
The grid tells you what the week should average — the coach helps you actually eat it.
What is zigzag calorie cycling?
Zigzag dieting — calorie cycling, calorie shifting, whatever your corner of the internet calls it — means varying intake day to day while holding a weekly average. Instead of 2,100 kcal every day for a fortnight, you might eat 1,800 on rest days and 2,600 on the day you squat, and finish the week at the same 2,100 average. The energy balance that drives weight change is the average, so the two plans predict the same outcome. What differs is how easy they are to live with.
How this calculator works
It sums the grid, divides by the number of days, and compares that average with your target — that comparison is the whole tool. Each row is then scored twice: against the target average, so you can see which days are paying for which, and against maintenance, so you can see the deficit each individual day carries. The weekly projection multiplies the average daily deficit by seven and divides by 7,700 kcal per kilogram of fat, the figure Max Wishnofsky published in 1958 and every calorie calculator has used since.
Does zigzagging actually do anything?
Not metabolically — that is the honest answer. The claim that varying intake "keeps your metabolism guessing" has never survived a controlled trial; adaptive thermogenesis tracks your average intake and your bodyweight, not the pattern. What zigzagging does buy you is real, though: a plan with a 2,600 kcal day in it survives a birthday dinner, and a plan without one does not. Trials of intermittent and cycled energy restriction consistently show similar fat loss to a flat deficit with better reported adherence, and adherence is the variable that actually decides who finishes a diet.
Building a week that works
Put the high days where the training is — the session you care about most gets the carbs, the rest days take the cut. Keep the spread modest to start: 400 to 600 kcal either side of the average is enough to feel like freedom without turning the low days into a fast. Do not let a low day drop below about 1,200 kcal for women or 1,500 for men, or you will start losing the protein and the sleep that make the diet work. And check the average weekly, not daily — one blown Saturday is a rounding error, four of them is a stalled diet.