Estimating 1rm from 5 or 10 reps?

When I was in my college health class, we did fitness
tests for cardio, strength, bodyfat, diet, sexual
health, smoking, etc. They didn't want anyone
hurting themselves by shooting for high 1rm (plus
it's tough to make an accurate starting guess if you
never lift). So they told us to put on a weight that
we thought we could do between 5 and 10 reps, then
they used a table that estimated our 1rm.

Something like "Okay, you were able to squat 100lbs
for 8 reps, so your 1rm is X, give or take 5lbs."

Anyone know of a table/chart that will tell 1rm from
number of reps you can do at a particular weight?

And are the estimates accurate. Thanks.

Of course, I finally find it right after posting this.From take the weight you did, and multiply it withthe coefficient associated with the number of repsyou did. The coefficients:Reps Coefficients
1 1
2 1.029
3 1.059
4 1.091
5 1.125
6 1.161
7 1.200
8 1.242
9 1.286
10 1.330
So for me, I can bench press 185lbs for 10 reps, then I fail. Using 190 times 1.330, my one rep maximum bench press is probably about 246lbs.

One of the charts on the page I referenced above also gives specialized coefficients for bench, squat, and deadlift.

According to that one, the bench coefficient for 10 reps is 1.325, so my 1rm is around 246, pretty close to the other estimate.

Here is another place to check:



I have Tudor Bompas Conditioning for Sports book and he has that chart as an appendix. It's kind of nice to have for figuring out starting weights for cycles and such. For example 10 reps with 225 would suggest a 300 lb. bench press capability, etc.