Intermittent Fasting Calculator
Plan your fasting schedule and track your progress
Select Fasting Protocol
16:8
16h fast, 8h eating
18:6
18h fast, 6h eating
20:4
20h fast, 4h eating
OMAD
23h fast, 1h eating
5:2
5 days normal, 2 days 500-600 cal
Custom
Create your own schedule
Set Fasting Start Time
About Intermittent Fasting
Intermittent fasting is an eating pattern that cycles between periods of fasting and eating. It doesn't specify which foods you should eat but rather when you should eat them.
Common intermittent fasting methods involve daily 16-hour fasts or fasting for 24 hours, twice per week.
Health Benefits
Weight Loss
By limiting your eating window, you typically consume fewer calories and boost metabolism.
Insulin Sensitivity
IF can reduce insulin resistance, lowering blood sugar levels and protecting against type 2 diabetes.
Cellular Repair
When fasting, your body initiates cellular repair processes like autophagy.
Heart Health
May improve various heart disease risk factors including blood pressure and cholesterol levels.
Brain Health
May increase brain-derived neurotrophic factor (BDNF), aiding brain health and preventing neurodegenerative diseases.
Fasting Protocol Details
16:8 Method
Fast for 16 hours each day, restricting your eating window to 8 hours. Most commonly, people skip breakfast and eat from noon to 8 PM.
18:6 Method
Fast for 18 hours with a 6-hour eating window. This typically means eating between 12 PM and 6 PM only, skipping breakfast and evening snacks.
20:4 Method (Warrior Diet)
Fast for 20 hours and eat within a 4-hour window. This is more challenging but can be effective for those adapted to fasting.
OMAD (One Meal A Day)
The most restrictive form of daily intermittent fasting. You eat just one meal per day, typically within a one-hour window.
5:2 Diet
Eat normally for 5 days of the week, then restrict calories to 500-600 per day for the other 2 non-consecutive days (typically Monday and Thursday).
Custom Protocol
Design your own fasting schedule based on your lifestyle and goals. Some people prefer 14:10 or other variations that fit their daily routine.
Spluxly’s free online Intermittent Fasting Calculator helps you plan, visualize, and track your fasting schedule with ease. Choose from six popular fasting protocols — 16:8, 18:6, 20:4, OMAD, 5:2, or a fully custom plan — set your fasting start time, and instantly receive a complete fasting and eating window schedule. A 24-hour color-coded timeline clearly maps your fasting periods in indigo and eating windows in green, while a real-time progress tracker keeps you updated on your current status, percentage complete, and time remaining throughout the day. Whether you’re a beginner exploring intermittent fasting for weight loss, improving insulin sensitivity, or supporting cellular health, this all-in-one tool makes staying on schedule simple and motivating. Completely free, no registration required.
How to Use the Intermittent Fasting Calculator Online
Setting up your personalized fasting schedule takes just seconds. Follow these simple steps:
- Select Fasting Protocol – Click your preferred protocol card: 16:8, 18:6, 20:4, OMAD, 5:2, or Custom
- Customize (Custom only) – Adjust fasting hours (12–23) using the slider; eating hours update automatically
- Set Fasting Start Time – Choose the time your fast begins (e.g., 8:00 PM)
- Click Calculate Schedule – Instantly view your fasting window, eating window, a 24-hour visual timeline, and a real-time progress tracker
Health Benefits of Intermittent Fasting
- Weight Loss – A restricted eating window naturally reduces calorie intake and helps boost metabolism
- Improved Insulin Sensitivity – Reduces insulin resistance, helping lower blood sugar and protect against type 2 diabetes
- Cellular Repair – Fasting triggers autophagy, the body’s natural process of cleaning out damaged cells
- Heart Health – May help improve blood pressure, cholesterol, and other key heart disease risk factors
- Brain Health – Can increase brain-derived neurotrophic factor (BDNF), supporting cognitive function and long-term brain health
Why Use Spluxly’s Intermittent Fasting Calculator?
- 6 Fasting Protocols – Supports 16:8, 18:6, 20:4, OMAD, 5:2, and fully custom fasting schedules for every lifestyle
- Custom Slider Control – Easily adjust fasting hours from 12 to 23; eating hours calculate automatically in real time
- 24-Hour Timeline Visualization – Color-coded chart clearly shows fasting (indigo) and eating (green) windows across the full day
- Real-Time Progress Tracker – Displays live fasting status, percentage complete, and exact time remaining throughout your fast
- Built-In Education – Includes detailed explanations of all protocols, proven health benefits, and important safety guidance
- 100% Free & Instant – No registration, no fees — your complete personalized fasting plan delivered in seconds