what does the community consider a normal SED rate for GCA/PMR?

0 to 15mm/hour

I believe less than 20 is normal. I was 2 when on 5 mg of pred.

The sed rate normals are based on a “normal population” assumption of generally healthy.
Your sed rate doesn’t always correlate with your symptoms or systemic degree of inflammation.
Your doctor considers what they expect to see for someone with known PMR as acceptable for their
condition. Less than 30 for most of us would be
acceptable if we had a minimum symptom score.
Your doctor’s guidelines reflect their experience with managing your disease. There are other tests for inflammation when the sed rate doesn’t correlate with
your symptoms. Consider requesting high sensitivity
CRP for cardiac risk evaluation with your lab checks.

I agree with seniormed. Many that have PMR do not show outside normal on sed rate or crp. But normal is what is your normal. I dont think most of had the tests before we got PMR so we dont have a baseline of whats your normal. Mine were normal. But an MRI of both shoulders showed bursitis. It just made diagnosis more difficult.

Under 20 ESR is considered normal by the lab my doctor uses, but over 40 or so is considered by several sources to be a positive indicator of PMR. I had all the PMR symptoms and an ESR of 25. My GP did not feel comfortable giving me prednisone at that level and referred me to a rheumatologist. By the time I got there it was 35 but I was self-medicating with 800 mg ibuprofen per day, which the rheumie thought was probably lowering the number. With my symptoms he was comfortable diagnosing me with PMR and giving me prednisone 20 mg, which started to bring relief within 6 hours.

A couple of other discussions on CRP and SED rates that might be helpful:
-- Ongoing pain with normal CRP and ESR - PMR?:
https://connect.mayoclinic.org/discussion/ongoing-pain/
-- CRP and SED levels:
https://connect.mayoclinic.org/discussion/crp-and-sed-levels/

The Mass General normal ranges on my patient portal are : ESR- 0-30 mm/h and for CRP less than 10 mg/L.

@tuckerp I think it is interesting that you commented about 'ever having these tests before'
My neighbor had CRP tested when she had flulike symptoms ( not covid , not flu so some mysterious infection) her CRP was higher than my highest level with PMR ! ( which was 34) , she is a nurse and her brother-in-law had GCA so she was very aware of any headache or pain in the temples. I bring it up because when I was had just tapered to zero mg Prednisone I had a flu with low fever for a few days ( not Covid) - My CRP and ESR were high as a result , but in addition I was having headaches and unusual pain in jaw in morning so ended up being evaluated for GCA - an unexpected TAB ! conclusion - not GCA but the flu-like illness and fever.

At my original PMR diagnosis, my ESR was 75. Two weeks and 30mg prednisone later, my ESR was 14 and all pain had been suppressed.
Now 16 months later, have tapered to 1, and ESR yesterday was 9. Only pains now are very minor, and are osteoarthritis in one shoulder and occasionally in wrists. No problem.

I think we are all so different. Probably to broad of a statement. For the first 68 yrs of my life I never had to have anything tested but a blood panel with cholesterol. That may not fit everyone. But I have seen comments where someone does not know what their CRP or sed rate were back when they were healthy. To give you a baseline. My numbers may have been elevated but they were in what they call "normal" range. we are probably saying the same thing.