How to pick your working weight

Step 1

Start from a set you actually did

Pick one set of this exact exercise from the last 90 days. Not a variation: your incline press says nothing reliable about your flat bench. The set should be between 3 and 10 reps. Above 10, the estimate below stops being trustworthy.

Turn it into an estimated max:

estimated max = weight × (1 + reps ÷ 30)

Example: you benched 60 kg for 8 last month. 60 × (1 + 8 ÷ 30) = 76 kg.

If your best recent set is older than 90 days, take 5% off the result (76 → 72 kg). Strength you haven't used in a while isn't all still there.

Step 2

Decide how hard today is

"Hard" isn't a feeling, it's how many reps you leave in the tank at the end of the set. Pick a day type, then a rep target inside its range:

Then work out the weight at which those reps would take you to failure:

working weight = estimated max ÷ (1 + (reps + reps left) ÷ 30)

Example, a hard day of 8 reps: 76 ÷ (1 + (8 + 2) ÷ 30) = 57 kg.

Or skip the maths and use the table: multiply your estimated max by the percentage.

Notice the harder day is the heavier one. If a plan gives you the same weight on a moderate day and a hard day, it's only changing the reps, and the hard day ends up easier.

Step 3

Round to a weight you can load

57 kg doesn't exist on most bars. Round to the nearest weight you actually have:

• Barbell: 2.5 kg steps, starting at the 20 kg bar. 57 kg → 57.5 kg.
• Dumbbells: the pairs in your rack. Above 10 kg most gyms go up in 2 kg or 2.5 kg steps.
• Kettlebells: the sizes that exist: 8, 12, 16, 20, 24, 28, 32 kg and so on.

With dumbbells, the number is per hand. Two 16 kg dumbbells is 16 kg per hand, not 16 kg total. Mixing the two up halves (or doubles) your working weight.

After that

When to add weight

Keep the same weight until you hit the top of the rep range on every set. Then add one step (2.5 kg on a barbell) and drop back to the bottom of the range. On a hard day, that's 57.5 kg × 6 → 8 → 10, then 60 kg × 6.

• One step at a time. Never jump two.
• Never add weight on a session where you missed the top of the range.
• A set that needs you to be more than 10% stronger than your best recent set isn't a plan, it's a test.

No recent set?

New exercise, or coming back

Pick a weight you're sure you could lift 10 times with good form. Do one set of 8 and stop with at least 2 reps left. Next session, use that set as your Step 1 set. It will underestimate you a little, which is the point: you earn the heavier numbers instead of guessing them.

If you've done fewer than about 20 lifting sessions in total, use about two-thirds of what the maths gives you. Early on, you're learning the movement, and the weight follows fast.

The last word

Your first set beats the maths

These numbers assume you've warmed up. If your first working set feels too heavy, take weight off for the rest of the sets, even if the formula said otherwise. The formula is a starting point. Your body on the day is the measurement. And if something hurts (not "hard", hurts), stop.