How many hours is fasting from dinner to lunch?

Last reviewed · Jun 29, 2026 · Not medical advice
Quick answer

Dinner to lunch is often around 16 hours if dinner ends near 8 PM and lunch starts near 12 PM.

Step by step

01 Write down your start time.
02 Choose your target fasting hours.
03 Calculate the end time and plan your first meal.

The longer answer

Dinner to lunch is often around 16 hours if dinner ends near 8 PM and lunch starts near 12 PM. A fasting calculator is useful because most fasting questions are really time-window questions. Once the start and target duration are clear, the rest is just tracking.

Tip

Use a timer rather than redoing fasting math while hungry.

Common mistake

Guessing the end time and accidentally stretching or shortening the fast.

Track in the app

Track planned vs actual start and end times.

Safety note
Educational only. People who are pregnant, breastfeeding, under 18, have diabetes, take glucose-affecting medication, have a history of eating disorders, or feel unwell should speak with a qualified clinician before fasting.

Related questions

Free on the App Store

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Fast Goblin answers the timing questions automatically — end times, windows, and streaks in one place.