How to Use the Free 1RM Calculator: Step-by-Step Guide & Strength Training Tips

How to Use the Free 1RM Calculator

We’ve just launched a brand-new interactive tool on SportsBrackets.net: the Free 1RM Calculator using trusted Brzycki and Epley formulas. This is how to use the free 1RM Calculator for you. It makes it simple and safe to estimate your one-rep max (1RM) for any lift. Perfect for NFL offseason training previews, Winter Olympics athlete prep insights, college basketball players building power, or your own gym progress tracking.

No more guessing percentages or risking a heavy max attempt without a spotter. Just input a submaximal set, and get an instant estimate to plan smarter workouts.

Quick Recap: What the Tool Does

The calculator estimates your 1RM (the heaviest weight you could lift once with good form) based on a weight you lifted for multiple reps. It uses two popular formulas:

  • Brzycki: Conservative and reliable for 2–10 reps → 1RM = Weight × (36 / (37 – Reps))
  • Epley: Slightly more aggressive for lower reps → 1RM = Weight × (1 + (Reps / 30))

These are backed by decades of strength training data and used in programs like 5/3/1, Starting Strength, and more.

How to Use the 1RM Calculator

Head over to the dedicated page here: 1RM Calculator (fully mobile-friendly and no sign-up needed).

  1. Enter the Weight Lifted
    Type in the amount you actually lifted (e.g., 225 lbs on bench press or 100 kg on squat). Units stay the same in the output: lbs or kg, your choice.
  2. Enter the Repetitions
    Input how many clean reps you completed to near or full failure (best results from 2–10 reps; ideal sweet spot is 3-8 for accuracy).
  3. Choose Your Formula
    Pick Brzycki (more conservative, great for beginners/intermediates) or Epley (often gives a slightly higher estimate, popular for advanced lifters). Try both to see the range!
  4. Hit Calculate 1RM
    You will see instant results like “Estimated 1RM: 255 (same units as input)”. The output appears right below the button.

Real-World Example (from the tool page):

1RM Calculator tool example
1RM Calculator tool example
  • Bench press: 225 lbs for 5 reps
    • Brzycki estimate: ~255–260 lbs
    • Epley estimate: ~262–265 lbs
      Use this to set training loads (e.g., 80% of 1RM for hypertrophy sets = ~204–212 lbs for 8–12 reps).

Tips for Accurate & Safe Use of the 1RM Calculator

  • Warm up thoroughly and use good form—garbage reps give garbage estimates.
  • Test with a weight that’s challenging but not max-effort (70–90% perceived effort).
  • Avoid >10 reps—formulas lose accuracy there (use a different method or test lower reps).
  • Track multiple exercises/sessions over time to spot trends and progress.
  • Compare formulas: If they differ a lot, average them or lean toward the conservative one for safety.
  • Safety first: This is an estimate only. Consult a coach or doctor before heavy lifting, especially if you’re new, injured, or pushing limits.

How This Fits Into Your Sports Routine

Knowing your 1RM helps tailor training:

  • NFL fans: Use it for Combine-style projections or offseason Bengals/Dolphins strength previews.
  • Olympics watchers: Track power/strength events like weightlifting or cross-country endurance base-building.
  • College hoops: Players boost vertical/explosiveness with percentage-based programs.

Check out related content on the site:

Give it a spin right now: Launch the 1RM Calculator and feel free to spread the word!

If you love tools like our Super Bowl Squares Generator and Bingo Card Maker, this is the next step in interactive content. More calculators and trackers coming soon. Stay tuned!

Happy lifting, and thanks for being part of the SportsBrackets community.

author avatar
Jacey Tine Author
Jacey Tine is a lifelong San Diego Padres and Florida Gators fan with 7+ years of sports coverage experience. At Sports Brackets, she delivers brackets, schedules, previews, and analysis across MLB, college football, NFL, WNBA, and more. Always with a fan-focused, reliable approach.