Planner inputs
Example data table
Sample inputs and a typical output pattern for a weekly plan.
| Setting | Example value | Why it helps |
|---|---|---|
| Protocol | 16:8 | Balances fasting benefits with meal flexibility. |
| Anchor | Eating starts at 12:00 | Keeps lunch as the first meal consistently. |
| Meals | 2 meals | Creates a simple rhythm: lunch and dinner. |
| Expected window | Eat 12:00–20:00, Fast 20:00–12:00 | Shows a clear daily cycle for planning. |
| Output | 7-day timetable with meal times and notes | Helps you follow the plan without guesswork. |
Formula used
- Eating window (hours) = 24 − Fasting hours.
- If the anchor is start: EatEnd = EatStart + EatingWindow.
- If the anchor is end: EatStart = EatEnd − EatingWindow.
- Fasting window runs from EatEnd to the next day’s EatStart.
- Meal times are centered in equal segments inside the eating window.
- BMR (Mifflin‑St Jeor): Men = 10w + 6.25h − 5a + 5, Women = 10w + 6.25h − 5a − 161.
- TDEE = BMR × Activity factor, and Target calories = TDEE × (1 ± Goal %).
w = weight (kg), h = height (cm), a = age (years).
How to use this calculator
- Select a fasting protocol (or set custom fasting hours).
- Choose an anchor rule and time for your eating window.
- Set the start date and number of days to generate.
- Add wake, bed, and training times for smarter notes.
- Enter your body metrics to estimate calories and macros.
- Click Generate plan, then export CSV or PDF.
This planner is for general fitness tracking, not medical advice.
Window length and consistency metrics
Common protocols range from 12:12 to 20:4, with 16:8 often easiest to sustain. This planner converts fasting hours into an eating window using 24 minus fasting. For a 16 hour fast, the eating window is 8 hours. Plan 7 to 14 days to quantify consistency.
Anchor time and schedule drift control
Anchor rules stabilize timing when life changes. If you anchor the eating start at 12:00, the end becomes 20:00 on a 16:8 plan. Daily shift applies minutes each day, while weekend shift adds extra change on Saturday and Sunday. Use small shifts, like 10 to 20 minutes, to reduce disruption.
Meal spacing and training alignment
Meal times are placed at the center of equal segments within the eating window. With 2 meals in an 8 hour window, points land near 14:00 and 18:00. Add a training time to flag whether sessions occur fasted or fed, and the post workout offset suggests when to refuel, such as 60 minutes after finishing.
Calorie target and macro starting points
Energy estimates combine BMR and activity. The calculator uses the Mifflin St Jeor equation, then multiplies by an activity factor like 1.55 for moderate movement. Goals adjust targets by plus 10 percent for lean gain, minus 10 percent for gentle loss, or minus 20 percent for fat loss. Macros start near 1.6 to 1.8 g protein per kg.
Hydration and caffeine timing guardrails
Hydration is set automatically at about 35 ml per kg, with limits to keep values practical. A 75 kg person lands near 2,625 ml per day, while a 90 kg person approaches 3,150 ml. Caffeine cutoff is counted back from bedtime; an 8 hour cutoff for a 23:00 bedtime points to 15:00.
Tracking outputs and weekly review process
Exporting the timetable supports weekly review. Use CSV for spreadsheets and PDF for sharing a clear plan. Compare planned windows with real adherence, then adjust anchor time, meal count, or shifts. When travel forces change, reduce the plan length to 3 to 5 days and regenerate to keep momentum strong. Compute adherence as followed days divided by planned days then improve gradually.
FAQs
Which protocol should I choose first?
Start with 14:10 or 16:8 if you are new. Pick the option you can repeat at least five days per week. After two consistent weeks, adjust fasting hours by one or two hours if needed.
Can I change my eating window on weekends?
Yes. Use the weekend shift to move the window earlier or later on Saturday and Sunday. Keep the change modest, like 30 to 60 minutes, to avoid a large Monday reset.
How are meal times calculated?
Meal times are centered within equal segments of the eating window. If you choose three meals, the planner places three evenly spaced targets between your start and end times to guide scheduling.
Is the calorie estimate mandatory?
No. Calorie and macro targets are optional guidance based on your body inputs and activity level. If you already track intake, use your preferred targets and focus on the timing plan.
What can I consume during the fasting window?
Most people keep fasting intake to water, plain tea, or black coffee. If you use medications or supplements, follow your clinician’s instructions. When in doubt, prioritize safety and hydration.
How do I use the graph effectively?
Use the eating window line to see daily timing at a glance. Meal markers show spacing. If the line drifts too late or early, reduce daily shift and pick a new anchor that matches work and sleep.