Strength training
Lander Formula: How to Calculate Your 1RM
The Lander formula gives conservative 1RM estimates, useful for prescribing loads with a safety margin.
What the Lander formula is and where it comes from
The Lander formula is a 1RM estimation model known for producing more conservative results than most. It emerged as part of the effort to refine strength-prediction equations in training settings.
Its conservative nature makes it attractive when working with beginners or in rehab contexts, where overestimating the load can carry more serious consequences than falling short.
The formula and how to apply it step by step
The Lander equation is: 1RM = (100 × weight) / (101.3 − 2.67123 × reps). You need the weight lifted and the reps performed close to failure.
Worked example: a client squats 160 kg for 6 reps. 1RM = (100 × 160) / (101.3 − 2.67123 × 6) = 16000 / (101.3 − 16.027) = 16000 / 85.273 = roughly 187.6 kg. For a heavy reference set, Lander returns about 202.8 kg.
Because of its coefficients, Lander stays stable in low and medium ranges, but it should not be used on very long sets where the relationship is no longer valid.
When to use the Lander formula
Lander fits well when you prefer to err on the cautious side. It is a good choice for beginners, return from injury or any situation where you would rather have a slightly lower target load than take a risk.
Strength
Conservative estimates that reduce the risk of prescribing excessive loads.
Limitation
It can underestimate 1RM in advanced athletes, leaving strength stimulus below optimal.
Best use case
Beginners, return-to-training phases and contexts where safety comes before peak performance.
Comparison with the other four formulas
For the same heavy reference set, Lander returns about 202.8 kg, a middle figure: above Brzycki and Lombardi (200 kg) but below O'Conner (205 kg) and Epley (206.7 kg).
Although it is considered conservative, in this specific example it lands in the middle. The lesson is clear: each formula's relative position depends on the rep count, so it is worth comparing them instead of trusting a single one.
How to use 1RM in your clients' programming
With a cautious estimate you can start blocks at slightly conservative percentages (65-80%) and increase based on the client's real response, controlled with RIR. It is a safe approach for building a strength base.
In TrainerStudio you store the estimated 1RM, generate loads and log every set to validate whether the prescription is appropriate or whether you can progress faster.