Free • Open Source • No signup

A weightloss tool that starts with BMI + Intermittent Fasting.

Calculate - BMI, fasting window, and calorie deficit. Save and go!

Latest US adult obesity

40.3%

NHANES Aug 2021–Aug 2023

Calculator ↓ Count Calories 🍔 Watches 🕒

How it works

Four Easy Steps

Calculate BMI

Enter height & weight

Pick fasting window

Example - 16:8

Choose calorie deficit

Slide to adjust pace

Save plan as PNG

Download your summary

Your plan

BMI calculator + fasting window

If you lift weights regularly and have achieved noticable muscle mass, this tool may be inaccurate. We recommend you find your local DEXA scan location for more accurate results.

BMI Calculator

Enter your weight and height.

US Units Metric

Weight

Height

Your BMI

–

Overweight

Healthy weight for your height

–

Based on BMI 18.5–24.9

To reach healthy range (≤24.9)

–

Intermittent Fasting Window

Select your fasting window.

Eating window start

Eating window end

Your timezone

Today’s plan

Pick a pattern to see your schedule.

Tip: Consistency beats perfection. Start with 12:12 or 14:10 if you’re new, and drink water or unsweetened tea during fasting hours.

Calordie Deficit Calculator

The median number for inactive calories a day is 1,800. This is your starting number.

In order to lose weight you must burn more calories than you consume.

Slide the bubble right to increase pace.

Approx. deficit scales with slider; higher = faster loss.

1800 kcal • ~0.0 lb/wk

0.0 lb/wk

1.0 lb/wk

2.0 lb/wk

Downloads an image summary you can save or share.

Disclaimer: BMI and fasting are screening/planning tools—not a medical diagnosis. Talk to a clinician about what’s right for you, especially if you have a medical condition or take medications.

Tools to Help

Calorie App and Fitness Watches

Photo to Calories App

Try this FREE App

Track your Calories

Fitness Watches on Prime

Nutrition guidance

Foods to Avoid

Based on reputable sources including USDA Dietary Guidelines, WHO, and major health organizations.

Ultra-processed snacks

Items like chips, candy bars, and packaged pastries are often high in added sugars, refined grains, and unhealthy fats while offering little nutritional value.

Sugary beverages

Soda, sweetened iced tea, energy drinks, and many fruit juices can pack large amounts of added sugar, which is linked to weight gain and metabolic issues.

Refined carbohydrates

White bread, white pasta, and many breakfast cereals have been stripped of fiber and nutrients, causing quick spikes in blood sugar and low satiety.

Fried fast food

Deep-fried items such as fries, fried chicken, and onion rings tend to be calorie-dense, high in trans fats, and low in beneficial nutrients.

Processed meats

Bacon, sausage, hot dogs, and deli meats often contain high sodium levels and preservatives, and frequent consumption is associated with higher chronic disease risk.

High-sugar desserts

Cakes, cookies, donuts, and ice cream are rich in added sugars and saturated fats, which can contribute to weight gain when eaten frequently.

Dairy

Some dairy products, particularly full-fat varieties like whole milk, cheese, and butter, can be high in saturated fats and calories. Excessive intake may contribute to weight gain and elevated cholesterol levels in certain individuals. Additionally, many flavored yogurts and milk-based drinks contain added sugars.

Note: Occasional treats are fine in moderation. Focus on whole foods—vegetables, fruits, lean proteins, and whole grains—for sustainable health and weight management.