Twenty hours fasting, four eating — the warrior pattern. A short, deliberate eating window each day. Enter when you stopped eating and find out exactly when your window opens.
Your 20-hour window opens at —
Who 20:4 suits: people who prefer one or two substantial meals to grazing. The 4-hour window is typically dinner plus an evening meal — many people find it simplifies food decisions to almost nothing.
A typical 20:4 day (last bite 8pm): your window opens at 4pm. Most of the fast happens overnight and through the workday. Hunger tends to come in waves — water and black coffee typically carry people through.
Twenty hours is advanced. If you're new to fasting, build up through 16:8 and 18:6 first — there's no prize for jumping ahead.
For healthy adults it's a common pattern, but longer daily fasts deserve respect: stay hydrated, eat enough in your window, and stop if you feel dizzy or unwell.
Two satisfying meals work well for most people. Undereating in a short window is the most common mistake — make the meals count.
Many people do. Others run it on weekdays and relax on weekends. The repeatable version beats the perfect version.
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Open in Fluent Fast →More calculators: 16:8 · 18:6 · 20:4 · OMAD · Fast end time · Eating window
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