Frequently Asked Questions
Find answers to common questions about the calorie calculator, how it works, and how your data is handled.
How does this calorie calculator work?
The calculator uses either the Mifflin-St Jeor or Harris-Benedict equation to estimate your Basal Metabolic Rate (BMR) based on your age, gender, height, and weight. It then multiplies your BMR by an activity factor to calculate your Total Daily Energy Expenditure (TDEE). Finally, it adjusts for your weight goal (loss, maintenance, or gain) and breaks down your target into macronutrient ratios.
Is my data private?
Yes. All calculations happen directly in your browser. No personal data is sent to, processed by, or stored on any server. Your calculator inputs are saved in your browser's local storage so you can return to them later, but this data never leaves your device. You can clear it at any time by clearing your browser data.
Is this professional dietary or medical advice?
No. This calculator provides estimates for informational purposes only. The results are based on generalised formulas and do not account for individual medical conditions, medications, metabolic variations, or specific nutritional needs. Always consult a qualified healthcare professional, registered dietitian, or doctor before making significant changes to your diet, especially if you have a medical condition.
How accurate are the results?
The Mifflin-St Jeor and Harris-Benedict equations are the most validated BMR formulas in nutrition science, but they are still estimates. Individual metabolism can vary by 10-15% from calculated values due to genetics, body composition, hormonal factors, and other variables. Use the results as a starting point and adjust based on your real-world results over 2-3 weeks.
When was the calculator last updated?
The calculator was last updated in March 2025. We regularly review the formulas, activity multipliers, and content to ensure accuracy and alignment with current nutrition science.
Can I export my results?
Yes. After calculating your results, click the 'Export PDF' button to generate a print-friendly PDF containing your inputs, calorie targets, and macronutrient breakdown. The PDF can be saved, printed, or shared with a healthcare professional or personal trainer.
How do I report an error or bug?
If you notice a calculation error, display issue, or any other bug, please use our contact form to report it. Select 'Report a bug or error' from the subject dropdown and provide as much detail as possible, including your browser, device, and the inputs you used.
What is the difference between BMR and TDEE?
BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest — just to keep you alive. TDEE (Total Daily Energy Expenditure) is your BMR multiplied by an activity factor, representing the total calories you burn in a day including all physical activity. TDEE is the number you should use for diet planning.
Which BMR formula should I use?
The Mifflin-St Jeor equation is recommended for most people and is the default in our calculator. It was developed in 1990 and has been validated as the most accurate formula for estimating BMR in the general population. The Harris-Benedict equation (revised 1984) is also reliable but tends to give slightly higher estimates, particularly for overweight individuals.
Can I use this calculator if I am pregnant or breastfeeding?
The calculator provides a baseline BMR and TDEE, but it does not automatically account for the additional calorie needs of pregnancy (roughly 300-450 extra kcal/day in the third trimester) or breastfeeding (roughly 450-500 extra kcal/day). You can use the calculator for your baseline and manually add these amounts. Always consult your healthcare provider for personalised guidance during pregnancy and postpartum.
Why does the calculator set a minimum of 1,200 calories?
Eating below 1,200 calories per day increases the risk of nutritional deficiencies, muscle loss, metabolic slowdown, and other health complications. The calculator enforces this as a safety floor. Very low calorie diets should only be followed under direct medical supervision.
Do you store my information on a server?
No. All calculations are performed in your web browser using JavaScript. Your inputs are saved only in your browser's local storage on your own device. We do not have access to your personal information, health data, or calculator inputs. We use analytics to understand site traffic but this does not include any of your calculator data.
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