Tools
Evidence-informed training tools
Calculators for the numbers lifters actually work with — maxes, effort, plates, volume and protein. Each one shows its formula, its assumptions, where the evidence is uncertain and the sources behind it.
Strength and loading
Estimate what you can lift and turn it into working weights.
- One-Rep Max CalculatorEstimate your one-rep max from any heavy set, including sets stopped short of failure (RIR/RPE), compare three equations and get working weights by reps.
- Calculates
- Estimated 1RM (Brzycki, Epley, Lombardi) and loads for 1–10 reps
- Useful when
- Setting training loads without testing a true max
- Evidence
- Rep-based equations are reasonably accurate up to about 10 reps (Mayhew 1995; Reynolds 2006).
- RPE & RIR CalculatorTurn one heavy set into an RPE chart for every rep target: estimated %1RM and load for RPE 6–10 (reps in reserve 0–4), with the limits of effort ratings explained.
- Calculates
- A personal RPE chart: approximate loads for 1–10 reps at RPE 6–10
- Useful when
- Programming by effort, or choosing the next set’s weight
- Evidence
- Lifters misjudge reps in reserve by about one rep on average (Halperin 2022).
- Percentage of 1RM CalculatorLoads for any percentage of your one-rep max, rounded to the plates you have, with the approximate rep range each percentage allows and why it varies by exercise.
- Calculates
- Loads at 50–100% of 1RM (or custom) and approximate reps
- Useful when
- Following a percentage-based programme
- Evidence
- Reps at a given %1RM differ by exercise and athlete (Shimano 2006; Richens 2014).
At the bar
Practical arithmetic for loading a barbell and getting ready for heavy sets.
- Barbell Plate CalculatorWhich plates to load on each side of the bar for any target weight, in kg or lb, using only the plates you own — with the closest possible load when the exact weight is not possible.
- Calculates
- Plates per side for a target weight, from your own plate set
- Useful when
- Loading the bar quickly and correctly
- Evidence
- Arithmetic, not research — accuracy depends on how close your plates are to their stated weight.
- Warm-Up Set CalculatorAn example warm-up progression for any working weight: ramping sets from the empty bar, rounded to loadable weights, with the plates for each set.
- Calculates
- An example ramp of warm-up sets with plates per side
- Useful when
- Preparing for heavy barbell sets without tiring yourself
- Evidence
- Warming up improved performance in most measures studied (Fradkin 2010); the exact ramp is coaching practice.
Muscle growth
Weekly training volume and protein — the two inputs the hypertrophy research measures most.
- Weekly Set Volume CalculatorAdd your exercises and weekly sets to see direct, indirect and fractional sets for each muscle, compared with the volume ranges studied in hypertrophy research.
- Calculates
- Direct, indirect and fractional weekly sets per muscle
- Useful when
- Checking whether a programme trains every muscle enough
- Evidence
- Counting indirect sets as half a set predicted growth best (Pelland 2025).
- Protein Intake CalculatorAn evidence-based daily protein range for your body weight and goal — building muscle, general training or losing fat while lifting — and how to split it across meals.
- Calculates
- Daily protein range (g/day and g/kg) and per-meal amounts
- Useful when
- Setting a protein target for building or keeping muscle
- Evidence
- Gains in lean mass levelled off around 1.6 g/kg/day in a meta-analysis of 49 trials (Morton 2018).
Numbers need context
Every calculator here gives an estimate or a starting point, never a prescription. The Evidence & Training guides explain what the research says about load, effort, volume and nutrition — and where it is still uncertain.