Tools
Calculators
No account required. Results are estimates. Use one tool, then the next.
Lose fat
Lose fat
Weight loss
Free weight loss calculator: estimate a week and date range to a goal weight using conservative weekly rates, not a promised deadline.
Anyone planning a fat-loss block who wants a week range, not a deadline.
12–18 weeks
Lose fat
Calories / maintenance
Maintenance calorie calculator and diet calculator: estimate TDEE with Mifflin-St Jeor, then compare 10–25% deficit scenarios. Default is 15%.
People who need a maintenance estimate and a 10–25% deficit range.
15% default
Build muscle
Build muscle
Protein
Get a daily protein range and a practical middle target, then split it across your meals.
Lifters who want a daily protein range they can actually eat.
g / day
Build muscle
Bulk / cut / recomp
Answer a few questions and get a path to consider, cut, lean gain, or recomp, with a clear next tool.
When you want both fat loss and muscle and need a path to try first.
Cut / lean gain / recomp
Get stronger
Which calculator should I use?
Which calculator should I use to lose weight?
Use the weight loss timeline calculator for a week and date range, then the calorie deficit calculator for a daily intake to try. Read how long fat loss takes if you want the method first.
How do I estimate a calorie deficit?
Estimate maintenance with Mifflin-St Jeor, or enter a known holding intake. ARC then shows 10%, 15%, 20%, and 25% below that. 15% is the default. Open the calorie deficit calculator.
How much protein should I eat?
The protein calculator uses 1.6–2.2 g/kg/day for resistance-trained gain or maintenance, and 1.8–2.4 g/kg/day while cutting. The headline is the middle of the range. See protein while cutting.
Should I bulk, cut, or recomp?
Answer a few questions in the bulk vs cut vs recomp calculator. It suggests a path from your goal, training experience, and recent weight trend, not a body-fat photograph. The bulk vs cut vs recomp guide explains the three options.
How is a 1RM estimated?
Enter a set of 1–10 reps. ARC runs Epley, Brzycki, and Lombardi, then shows the median as the headline. That is an estimate, not a tested max. Use the 1RM calculator.