Intermittent Fasting Calculator: Keto, Paleo, Vegan & Carnivore

Our free intermittent fasting calculator is the simplest way to combine time‑restricted eating with the right calorie and macro targets—no matter which diet you follow. Whether you need an intermittent fasting schedule calculator to plan your 16:8 or 5:2 routine, a beginner‑friendly keto calculator for beginners, a clean paleo diet calculator, a personalised vegan diet calorie calculator, or a zero‑carb carnivore diet macro calculator, this all‑in‑one tool has you covered. We also include a time‑restricted eating planner, an alternate‑day fasting tool, a low‑carb macro calculator, a plant‑based nutrition calculator, and a primal diet tracker—all working together to make sure your fasting and food choices line up perfectly.

What Is an Intermittent Fasting Calculator?

An intermittent fasting calculator takes the guesswork out of eating windows. Instead of just telling you when to fast, it calculates exactly how many calories and grams of protein, carbs, and fat you need within your eating window to reach your goal—weight loss, maintenance, or muscle gain. For example, if you’re doing the popular 16:8 fasting method, you might eat between noon and 8 p.m. Our tool uses your TDEE, goal, and diet type to generate a complete time‑restricted eating macro plan. We even offer options for OMAD (one meal a day), 5:2 diet planning, and alternate‑day fasting calorie splits, so you can experiment safely and sustainably.

Intermittent Fasting Schedule Calculator: Find Your Perfect Window

Choosing the right fasting protocol can be overwhelming. Our intermittent fasting schedule calculator simplifies this by recommending a window based on your lifestyle. Night owls might thrive on a 14:10 schedule, while busy professionals often prefer 18:6 fasting. If you’re new to fasting, a 12:12 circadian rhythm fast is a gentle start. Simply enter when you typically wake up and go to bed, and the tool suggests an eating window that fits your natural rhythm. It also provides a fasting schedule for weight loss and a muscle‑sparing fasting protocol for active individuals, because timing matters almost as much as total intake when you’re trying to preserve lean mass.

Keto Calculator for Beginners: Start Low‑Carb the Right Way

If you’re starting a ketogenic diet, a keto calculator for beginners is your new best friend. It takes your calorie goal and converts it into a classic keto macro split—roughly 70‑75% fat, 20‑25% protein, and 5% carbs (usually under 20‑50 grams of net carbs). Our keto macro planner also shows you exactly how many grams of fat, protein, and total carbs you need each day, with a special focus on net carbs for ketosis. Beginners often underestimate how much fat they need, and the tool gently guides them away from the common mistake of eating too much protein and not enough fat. You’ll also find a keto food list for beginners, a keto electrolyte guide, and a keto adaptation timeline right in the results.

Paleo Diet Calculator: Eat Like Your Ancestors, with Precision

The paleo diet emphasises whole, unprocessed foods—meat, fish, vegetables, fruits, nuts, and seeds—while eliminating grains, dairy, legumes, and refined sugar. Our paleo diet calculator doesn’t just count calories; it also ensures your macro split aligns with a nutrient‑dense, satiating approach. A typical paleo macro breakdown might be 30% protein, 30% carbs, and 40% fat, but you can adjust the sliders. It also shows you how to meet your paleo fibre intake without grains, and suggests paleo carb sources like sweet potatoes and fruit. Whether you’re using paleo for weight loss, autoimmune support, or athletic performance, the calculator provides a hunter‑gatherer meal plan structure you can follow easily.

Vegan Diet Calorie Calculator: Plant‑Powered and Personalised

A well‑planned vegan diet can meet all your needs, but it requires a bit more attention to protein and certain micronutrients. Our vegan diet calorie calculator sets your daily calorie target and then adjusts the protein recommendation slightly upward—by about 10‑15%—to account for the lower digestibility of some plant proteins. It also highlights vegan complete protein sources (tofu, tempeh, quinoa, seitan, lentils + rice) and calculates your plant‑based iron and B12 considerations. You’ll get a vegan macro split that can be higher in carbs—often 25% protein, 55% carbs, 20% fat—perfect for active individuals who need plenty of fuel. The vegan meal planner feature even suggests a sample day of eating that hits all your numbers.

Carnivore Diet Macro Calculator: Zero Carbs, All Meat

For those following an animal‑based elimination diet, a carnivore diet macro calculator is essential because the standard macro ratios don’t apply—carb intake is virtually zero. Our tool sets carbs to zero and splits calories between protein and fat, often in a ratio like 30% protein, 70% fat by calories. Because the carnivore diet can be high in saturated fat, the calculator also lets you adjust fat sources (e.g., leaner cuts vs. fatty ribeye). It calculates your carnivore protein target and warns if protein is too low (which can cause fatigue) or too high (which can kick you out of ketosis for some individuals). We also include a carnivore diet food list and a nose‑to‑tail nutrient guide to ensure you’re getting enough vitamins and minerals without plants.

Additional Diet Calculators for Every Eating Style

Beyond the big five, our platform includes a Mediterranean diet calorie planner, a low‑FODMAP meal calculator, a whole30 macro tracker, a flexitarian protein calculator, and a DASH diet sodium and calorie tool. Each one takes your personal stats and goal, then tailors the numbers to fit the philosophy of that diet. A slow‑carb diet calculator, a cyclical keto planner, and even a metabolic confusion calorie splitter are available for advanced users. The goal is to give you a diet‑specific nutrition calculator that doesn’t force you into a generic template—you get a plan that respects the rules of your chosen way of eating.

How to Use Our All‑In‑One Fasting & Diet Calculator

1. Enter your age, sex, height, weight, and activity level. The tool instantly calculates your TDEE.
2. Choose your diet: Intermittent Fasting, Keto, Paleo, Vegan, Carnivore, or another option. If you select intermittent fasting, pick your fasting protocol (16:8, 5:2, OMAD, etc.) to activate the intermittent fasting schedule calculator.
3. Set your goal (weight loss, maintenance, muscle gain). The calorie target adjusts automatically.
4. Fine‑tune your macro split if desired, or let the tool use the optimal default for your chosen diet. The keto macros calculator, vegan macro planner, or carnivore diet macro calculator will display your numbers in grams.
5. View your personalised daily plan: eating window (if fasting), calorie target, grams of protein, carbs, fat, and a sample meal framework.

Making Fasting and Dieting Work Together

One of the biggest mistakes people make is combining intermittent fasting with a diet that doesn’t match. For example, trying to eat an entire day’s worth of keto macros in a four‑hour window can be tough on digestion. Our fasting + keto synergy guide explains how to adjust meal frequency and macro timing so you don’t feel uncomfortably full or short on energy. Similarly, a vegan OMAD protocol can work if you focus on calorie‑ and protein‑dense foods like legumes, tofu, and seeds. The tool provides practical fasting‑diet combinations that actually work, along with warnings about combinations that might lead to nutrient shortfalls.

Common Questions About Fasting & Diet Calculators