Free Tools
Supplement Calculators
Free, evidence-based tools to cut through the label noise — from supplement dosing (protein, creatine, beta-alanine, citrulline, caffeine) to nutrition, strength and body composition.
No sign-up, no maths. Enter your weight, pick your goal, and each tool points you to the right products and the buyer's guide behind the numbers.
Enter your bodyweight to see your target.
Supplement tool
Supplement Timing Planner
Pick what you take and when you train — get a daily schedule, plus the timing myths you can ignore.
Supplement tool
Combination Checker
Can you take these together? Honest verdicts on mixing your supplements, plus the caffeine and double-dosing traps.
Supplement tool
Creatine Dosage Calculator
Your exact loading and maintenance dose for your bodyweight, plus days to full saturation.
Supplement tool
Beta-Alanine Dosage Calculator
Your daily dose for your bodyweight, how to split it to control the tingles, and days per tub.
Supplement tool
Citrulline Dosage Calculator
How much of your form to take for a real dose, and whether your pre-workout underdoses it.
Supplement tool
Caffeine Calculator
Your effective pre-workout dose, then a half-life clock for when to stop before bed.
Nutrition tool
Protein Calculator
Get your daily protein target in grams for building muscle or losing fat, plus a per-meal split.
Nutrition tool
TDEE & Macro Calculator
Find your maintenance calories, then your protein, carb and fat targets for any goal.
Strength tool
One-Rep Max Calculator
Estimate your 1RM from any set, then get your training loads at every percentage.
Strength tool
Barbell Plate Calculator
Enter your target weight and bar — see the exact plates to load on each side.
Strength tool
RPE Calculator
Rate a set by reps and RPE to estimate your 1RM, then get the load for your next set.
Strength tool
DOTS Score Calculator
Score your squat, bench and deadlift total against your bodyweight — the modern Wilks.
Body composition tool
Body Fat Calculator
Estimate your body fat % from a tape measure — plus your category, lean and fat mass.
Body composition tool
FFMI Calculator
Score your muscle mass for your height and see where you sit against the natural limit.
Body composition tool
BMI Calculator
Your Body Mass Index in seconds — plus the honest reason lifters should not trust it.
Protein target
Total daily protein is what drives muscle growth and recovery, far more than the timing of any single shake. Most lifters do well on 1.6 to 2.2g per kg of bodyweight, climbing toward 2.4g/kg on a cut to hold onto lean mass. Whole food should do most of the work; a whey shake is simply the easiest way to close the last 25 to 50g gap.
Creatine dose
Creatine is the rare supplement where the dose is flat: 3 to 5g of monohydrate a day, every day, regardless of how big you are. A loading phase only changes how fast your stores fill, not the end result. Because the dose is small and constant, the only thing that really separates products is purity and price per gram.
Caffeine range
Caffeine is the one pre-workout ingredient that reliably works, at roughly 3 to 6mg per kg of bodyweight. More is not better: past 400mg in a serving the downsides start to win, which is exactly why our scoring penalises over-caffeinated pre-workouts. Keep your total from all sources under 400mg a day, and switch to stim-free if you train late.
Common questions
How much protein should I eat per day?+
For most lifters, roughly 1.6 to 2.2 grams of protein per kilogram of bodyweight daily supports muscle. On a fat-loss phase it is pushed higher (around 2.0 to 2.4 g/kg) to protect lean mass. Our protein calculator turns that into a gram target for your weight and goal.
How much creatine should I take?+
3 to 5 grams of creatine monohydrate every day is the evidence-based maintenance dose, and it does not change with bodyweight. An optional loading phase of 20g a day (4 x 5g) for 5 to 7 days saturates your muscles faster, but is not required.
How much caffeine is safe before a workout?+
The studied pre-workout range is about 3 to 6mg of caffeine per kilogram of bodyweight. We treat 400mg in a single serving as the ceiling, and EFSA puts the safe daily limit for healthy adults at 400mg from all sources. If you train in the evening, a stim-free option protects your sleep.
Are these calculators medical advice?+
No. They are general, evidence-based starting points for healthy adults, not personalised medical or clinical advice. If you are pregnant, have a health condition, or take medication, speak to a qualified clinician before changing your supplement intake.
Know your numbers?
Now find the products that hit them. Every supplement we track is scored 0–100 on how closely its doses match the evidence — or let the wizard build your whole stack.
Informational only — not medical advice. Figures are general starting points for healthy adults. Buy links are affiliate links; we may earn a commission at no extra cost to you.