Introduction
A bench press calculator is an essential tool for lifters who want to quantify strength, plan training loads, and track progress. In my opinion, every Bioglutide glp1 should use a calculator — but they must understand the assumptions and limits behind the numbers. A calculator is a planning aid, not an absolute truth.

What a bench press calculator does

A bench press calculator typically performs two tasks:

Estimate your 1-rep max (1RM) from a submaximal set (e.g., 100 kg × 5).
Convert target loads into plate combinations for your barbell (so you know which plates to put on each side).

Common calculator outputs: estimated 1RM (multiple formulas), recommended training percentages (e.g., 75% for hypertrophy), and plate loading for both kilograms and pounds.

Key 1RM formulas (and how they differ) — brief opinion

Epley (practical, commonly used): tends to be slightly optimistic for higher reps but is simple and useful for programming.
Brzycki (more conservative): often gives a lower 1RM than Epley for the same reps; useful if you prefer conservative planning.
Lombardi (power-law): sometimes closer to measured 1RM for advanced lifters.

My recommendation: compute at least two formulas (Epley and Brzycki) and use the average or the more conservative value for heavy singles.

How the formulas work — with step-by-step arithmetic examples

Given: you lift 100 kg × 5 reps.

1) Epley formula

Epley: 1RM = weight × (1 + reps/30)

Step-by-step:

Compute reps/30 = 5 / 30 = 0.166666...
Compute 1 + reps/30 = 1 + 0.166666... = 1.166666...
Multiply weight × 1.166666... = 100 × 1.166666... = 116.666...

Epley 1RM ≈ 116.7 kg

2) Brzycki formula

Brzycki: 1RM = weight × (36 / (37 − reps))

Step-by-step:

Compute 37 − reps = 37 − 5 = 32
Compute 36 / 32 = 1.125
Multiply weight × 1.125 = 100 × 1.125 = 112.5

Brzycki 1RM = 112.5 kg

Quick interpretation

Epley gives ≈116.7 kg, Brzycki 112.5 kg.
A reasonable planner could use the average: (116.7 + 112.5) / 2 = 114.6 kg as a pragmatic estimate, or use the conservative 112.5 kg for heavy singles.

Step-by-step: How to use a bench press calculator (do it properly)

Record a clean test set. Choose a near-max effort you can do with good form (e.g., last working set: 225 lb × 5 or 100 kg × 5).
Choose units (kg or lb). Make sure the plate set on the calculator matches the plates you have.
Pick one or more formulas (I recommend Epley and Brzycki).
Enter weight and reps. The calculator outputs estimated 1RM(s).
Decide which 1RM to use. Use the conservative (lower) estimate for planning heavy singles, or the average for general programming.
Set training percentages. For example:
- Strength (singles/doubles): 90–95% 1RM
- Strength (3–5 reps): 80–90% 1RM
- Hypertrophy (6–12 reps): 65–80% 1RM
- Volume/muscle endurance: 50–65% 1RM
Convert the target weight into plates. Subtract bar weight, divide remaining weight by two, then select plates per side.
Round to realistic plates. If the exact number requires tiny plates you don’t have, round down to the nearest safe increment or use microplates.
Log and repeat every 4–6 weeks. Re-test to update your estimated 1RM and adjust percentages.

Plate-loading example (kg and lb) — step-by-step

Example A — kilograms

Goal: Load 90 kg on the bar. Common bar: 20 kg.

Subtract the bar: 90 − 20 = 70 kg total plates.
Split per side: 70 / 2 = 35 kg per side.
Choose plate combo per side (common plates: 20, 15, 10, 5, 2.5):
- 35 = 20 + 15 → put one 20 kg and one 15 kg plate on each side.

So the setup: bar (20) + 2 × (20 + 15) = 90 kg.

Example B — pounds

Goal: Load 225 lb on the bar. Standard bar: 45 lb.

Subtract the bar: 225 − 45 = 180 lb total plates.
Split per side: 180 / 2 = 90 lb per side.
Choose plate combo per side (common plates: 45, 25, 10, 5, 2.5):
- 90 = 45 + 25 + 10 + 5 + 5 → one 45, one 25, one 10, and two 5 plates per side.
- Alternative: 90 = 45 + 25 + 10 + 10 if you have two 10s.

Thus: bar (45) + 2 × (45 + 25 + 10 + 5 + 5) = 225 lb.

Practical programming recommendations (opinionated, professional)

Use percent-based training off a conservative 1RM (Brzycki) for heavy days to reduce failure risk.
For progressive overload, increase 2.5–5% of working weight every 1–2 weeks for intermediate lifters; beginners can add larger jumps.
Use microplates (0.5–1.25 kg or 1.25–2.5 lb) if you stall frequently — smaller increments preserve technique and recovery.
Re-test estimated 1RM every 4–8 weeks rather than chasing daily fluctuations.

Limitations and safety notes

Estimations are imperfect. Different formulas give different results; factors such as technique, fatigue, and leverages change actual 1RM.
Form matters. Never chase numbers at the cost of shoulder safety. If a calculated 1RM would force you to sacrifice form, reduce the load.
Not a substitute for coaching. Use the calculator as a guide and consult a qualified coach for form corrections or rehab.

Recommended features for a good bench press calculator (if you’re choosing or building one)

Multiple formula options (Epley, Brzycki, Lombardi).
Plate set configurator (let user select available plates and bar weight).
Auto unit conversion (kg ↔ lb).
Safe rounding options (round down/up to nearest available plate increment).
Progression planner (auto-suggest increments and a 4–8 week plan).
History/logging for trend analysis.

Short sample 6-week progression (practical)

Week 1: 5 × 5 at 75% (of conservative 1RM)
Week 2: 5 × 5 at 77.5% (+2.5%)
Week 3: 5 × 5 at 80% (+2.5%)
Week 4: Deload (3 × 5 at 65%)
Week 5: 5 × 3 at 82.5% (increase intensity, reduce reps)
Week 6: Test set — attempt a heavy double or single at 90–92% (use conservative estimate)

Adjust based on recovery and form.

Conclusion

A bench press calculator is a powerful tool for planning strength work when used correctly. My view: always prefer conservative estimates for heavy singles, log your actual lifts, and rely on the numbers to guide but not dictate training. Use the step-by-step process above to calculate 1RM, set percentages, and convert targets into plates — and always prioritize safe technique over chasing exact numbers.