# 1RM Calculator Way Off

I can do 110 for 5, that’s calculated to 124 max.

In reality I max at 145. So that makes the calc 15% inaccurate.

How accurate is this for you guys?

Forgot the calculations. Just lift what you can lift. You take two guys who can bench 300. One guy will do 225x8 and the other will get 225x12. There is no universal calculation

It can be inaccurate, it depends on your fiber type distribution, training regime, momentary condition, the exercise you’re testing.

But in most cases it gives you conservative estimation of your 1RM, which is better, in my opinion. I’d like to complete the first set and adjust the weight myself instead of risking injury with way off weight.

One-rep max calculators are based off percentages and each percentage is given a number of reps. Usually they’ll give you a decent estimate, but if you know your body you should never need one.

1 rep calculators just don’t work. If you want to know your max, you need to max. After awhile, you’ll be able to guessimate fairly well if you have a good training log.

For example, if you bench 225 x 5 and can max 255 you are probably around 285 or so if you can do 255 x 5.

[quote]saps wrote:
Forgot the calculations. Just lift what you can lift. You take two guys who can bench 300. One guy will do 225x8 and the other will get 225x12. There is no universal calculation[/quote]

Agreed. In my experience, the only accurate estimation of my 1RM is based off my 2RM.

[quote]dfreezy wrote:
saps wrote:
Forgot the calculations. Just lift what you can lift. You take two guys who can bench 300. One guy will do 225x8 and the other will get 225x12. There is no universal calculation

Agreed. In my experience, the only accurate estimation of my 1RM is based off my 2RM.[/quote]

The only rep calculator is your own custom model from experience.

also you have good days and bad days where you will lift a little more or less
those thingsa re supposed to be used as a guide-line only and not really an accurate mapping of ones abilities

it depends on the lift, on the individual.

for example i can do 5 reps with 65kgs overhead press but i may not even be able to do 1 with 67.5kgs(ok that only happened when i needed a deload but still its not far from true)

on squats my 1 RM from my 5 RM are pretty close compared to most people. granted many things could play a role every time you lift. sleep, food before workout, how tired your muscles/CNS are, how quickly you do your sets, how much rest you get inbetween sets, how tight you are, technique, form etc.

The higher the reps the more off the 1rm will be.

The 1rm calculators seem to be off for me, but a good gauge for my 1rm is my 3rm. If I can hit something for 3, I can pretty much gaurantee I can add between 10-15% and hit it for a single.

It is interesting. We track training cycles vs. meet results pretty carefully for our lifters.

This typically allows us to guage how much each consecutive rep contributes to their max.

In other words, if the last heavy day a lifter performs 500#'s for a triple, what does this mean?

For some lifters it means they get 5-7#'s per rep after the first I have had lifters as high as 15-18#'s.

It depends on a lot of factors and is a large component of why powerlifters are generally better off with some consistency in their approach to peaking and, in the instance where conjugated is used, determining ‘indicator’ movements.

For 1-5 reps I find that the chart on this site works really well for the big three (you have to scroll all the way down). One Rep Max Calculator

Those calculators serve only as guides. Guides.

I would be lucky to hit 225x8, yet can do 300. Like what undeadlift said, they are simply guides.

Now a new question: If higher reps 5+ force me to use a much lighter weight should I focus on triples and lower for maximum gains?

I’m doing madcow 5x5 right now, think it would hurt to make that 5x3?

[quote]LiftSmart wrote:
Now a new question: If higher reps 5+ force me to use a much lighter weight should I focus on triples and lower for maximum gains?

I’m doing madcow 5x5 right now, think it would hurt to make that 5x3?[/quote]

Then you wouldn’t be doing Madcow 5x5, if your not happy with 5x5 then look for another program.

Maybe something like Sheiko.

1RM calculator is terrible, only use it with low reps, such as, 2-3. the best way is just to lift using progression.

[quote]MrBaseball0 wrote:
The higher the reps the more off the 1rm will be.[/quote]

This man speaks the truth. They are pretty good to go from 3 rep max to 1 RM.

In my case the formula gives a weight that is like 15-20% lower when I use reps of 8 or more.

For those interested, you can make your own formula for various body parts/exercises without ever taking your 1 rm max.

You just need to do (on 3 different workouts):

• 1 set to failure with a weight that allows 8-15 reps.
record weight and reps.

• 1 set to failure with a weight that allows 5-8 reps.
record weight and reps.

• 1 set to failure with a weight that allows 2-5 reps.
record weight and reps.

Obviously you need to use the same form and rep speed on all 3 tests.

Plot the weight vs reps (x-axis) with excel or any spreadsheet or graphing software.

Plot a line through the points and where the line intercepts 1 rep that is your 1 RM max.

You can go a step further and divide all the weights by the 1 RM to give a %1RM. So if you plot this vs the number of reps it will give a line whose slope will be your own formula do determine your 1 RM from any rep range. Most spreadsheets will give this formula automatically.

You probably don’t need to test for all exercises. I would test 1 press, 1 curl, leg extension and leg curl and apply that to all other corresponding exercises.

In general once you have done this at an advanced level you don’t need to restest as the slope (your relationship between max strength and endurance will not change significantly).

[quote]goya wrote:
You probably don’t need to test for all exercises. I would test 1 press, 1 curl, leg extension and leg curl and apply that to all other corresponding exercises.[/quote]

Better yet, test your Squat, Bench and DL.