14:10 Intermittent Fasting Calculator

A 14:10 window is barely a departure from ordinary eating: finish dinner by eight, eat again at ten the next morning, and you are already there. Because the window is wide, the spontaneous cut in intake is small, since you still have room for the meals you normally eat, just with less late-night grazing. Reviews of intermittent fasting put the reduction across protocols at 10–30%, and a gentle 14-hour fast sits at or below the bottom of that range (Varady et al., 2021); this calculator estimates a 5–15% cut for 14:10. For the worked body — maintenance about 1,990 calories — a 10% cut is around 200 calories a day, landing intake near 1,790. That is a modest deficit, but it is a genuine one, and its great virtue is that almost anyone can keep it up. Enter your own maintenance and the calculator sizes the gap for you.

A 200-calorie daily deficit is about 1,400 calories a week, which at roughly 7,700 calories per kilo of fat comes to about 0.18 kg — near 0.4 lb — every week for the worked body. On paper that looks small, and it is: perhaps a kilo over five or six weeks. But a gentle deficit has two quiet advantages. It is easy to hold, so it keeps working month after month rather than collapsing in a rebound, and it is far less likely to cost muscle or leave you hungry. Slow, steady loss you never have to fight for often outperforms an aggressive plan you abandon. Confirm the maintenance the estimate rests on with the TDEE Calculator, then read your weekly range above.

When to Tighten the Window

If 14:10 feels effortless and you want a faster result, the right move is to tighten the window to 16:8, not to start eating too little inside your current one. Shrinking the eating window is what fasting is designed to do — it trims intake naturally — whereas slashing calories on top of an already-gentle window can leave you hungry and prone to rebound. Step down one window at a time and let the scale trend guide the pace. Track your milestones as you go with the Weight Loss Percentage Calculator.

Weight loss is decided over months, not days, and the schedule that survives those months is the one that wins. A 14:10 window asks very little of you — no skipped breakfasts, no white-knuckle fast days — so it rarely triggers the hunger and burnout that end stricter plans. For many people, especially those new to fasting, the slow-but-permanent path of 14:10 delivers more total loss over a year than a punishing window they quit in three weeks. Keep protein reasonable, judge the trend over a fortnight, and let consistency do the work.