You fast for 16 hours and eat within an 8-hour window each day.

What's a typical 16:8 schedule?

Noon to 8 pm is common, but 10 am to 6 pm or 9 am to 5 pm work just as well. Pick what fits your day.

Is 16:8 good for beginners?

It can be, but many people find it easier to start with 12:12 or 14:10 and build up over a week or two.

How many meals should I eat in 8 hours?

Two meals and a snack, or three smaller meals, are both common. Focus on balanced, filling foods.

Can I do 16:8 every day?

Many people do, while others do it five days a week. Choose a rhythm you can sustain and that suits your health.

Will 16:8 guarantee weight loss?

No. It's a tool for structuring meals. Results vary and depend on overall diet, activity, sleep and health.

16:8 Fasting Calculator – Your 16 Hour Fast & 8 Hour Window

16:8 is the most popular way to try intermittent fasting, and for good reason. Sixteen hours sounds long, but when most of it happens overnight, it often comes down to a later breakfast and an earlier dinner. This calculator is set to 16:8 by default. Enter when you finished eating and it shows your next meal, when your 8-hour window closes and a live countdown.

How 16:8 works

You stop eating at a set time in the evening, sleep, and keep the fast going through the morning with water, black coffee or plain tea. Sixteen hours after your last meal, your eating window opens and you have eight hours for your meals. Then the cycle repeats. Finish dinner at 8 pm and you'd eat again at noon the next day, closing the window at 8 pm.

Example 16:8 schedules

Noon – 8 pm: the classic, keeps evening meals social.
10 am – 6 pm: a good balance for people who get hungry mid-morning.
9 am – 5 pm: suits early risers and those who sleep better after an early dinner.
Weekend flex: slide the window an hour later on Saturday and Sunday if plans run late.

Easing into 16 hours

Jumping straight to 16 hours can be uncomfortable if you're used to breakfast at 7 am. Try 12 hours for a few days, then 14, then 16. You can switch the method in the calculator to see each step. Most people notice that hunger becomes more predictable after the first week or two.

What to eat in your 8-hour window

Because you're eating in a shorter period, each meal matters more. Build plates around protein (eggs, fish, poultry, tofu, beans, yogurt), lots of vegetables, whole grains or starchy vegetables, and a little healthy fat. Breaking the fast with a balanced meal, rather than something very sugary, tends to keep energy steadier. Our meal plan generator can create a week of 16:8-friendly ideas.

Common 16:8 pitfalls

Not drinking enough: you lose the water normally found in breakfast foods, so keep sipping.
Overeating at the first meal: plan it in advance to avoid grabbing whatever is nearby.
Short sleep: it can make the morning stretch much harder.
All-or-nothing thinking: a 15-hour fast still counts. Just keep going.

Is 16:8 right for you?

For many healthy adults it's a manageable routine. It isn't suitable for everyone, though. If you're pregnant or breastfeeding, under 18, managing diabetes, taking medications affected by meal timing or have a history of disordered eating, talk to a healthcare professional before starting.

Want a schedule tailored to your routine? Take our one-minute quiz for a suggested method and eating window.

Tracking your first month

Give 16:8 a fair trial of three to four weeks before judging it. Use the fasting timer to log each fast and note how you feel: energy in the late morning, hunger before the first meal, sleep quality and mood. If most days feel manageable, you've found a sustainable rhythm. If you're regularly struggling, step back to 14:10 for a while; that is a perfectly good routine in its own right. Some people also find that pairing the start of the window with a short walk, or the end of it with a set bedtime routine, makes the schedule feel automatic. The goal is a habit that fits quietly into your week, not one that dominates it.

16:8 Fasting Calculator