This is the reason our Board discourages listing total sq footage:

  http://www.cbc.ca/news/canada/calgary/realtor-misrepresents-square-footage-1.3487389

We measure each room and state which level it is on and I provide a floorplan too. 

No

I do not measure myself. All of my homes are professionally measured and have professional floor plans. Much less liability and buyers love the floor plans.

Because I do know how to read a tape measure and multiply...I do my own

I am a pro, so i measure my own.

Cite the source - typically public records or an appraisal.   

We have information provided by our county that is automatically filled into our MLS listings. I include a disclaimer since I can't make any corrections manually.

Frank,

We always left the measuring to the pros...it minimizes potential litigation and problems.  A

I use  a sonic measuring device. No errors.

another reason I loved being a listing agent for "new construction"....the square footage was directly from the architectural drawings....

The assessor does a decent job. Add "buyer to verify" and were done here

I measure my listings.

Frank Rubi Measurements are done by the room size. For residential properties, total square footage doesn't carry much weight. Many agents include the area below grade which is a no, no. For commercial real estate square footage is important and is strictly measured by the BOMA standard.

I go with the tax record usually - that way I can defer to that if I am challenged or disputed

I use the tax assessor's. If square footage is different if I measure it, frankly, I don't want the responsibility or liability on behalf of my clients selling or buying it as such. They can hire an expert to do so.

I do that myself

Neither

I would normally use the figures from the tax records.

Neither.

I repeat what is pubic information and include in the text (not footer) "Best effort made but ALL things of value to buyer should be verified by the buyer."

How big is this house? Stretching arm fully I reply "THIS BIG." Take a look at the paper in your hand. I think there is a number published there. Do you think it is big enough for your needs?"

I'm not that daft that I can't handle a tape measure thank God.

I measure room sizes with help from sellers.

We measure when no other info is available, this disclaimer is added. Measurements not warranted , buyer to verify all measurements.

Previous listing is a reference, I check it if it seems doubtful.

 I think that most folks take the square footage off the tax tables.

No I do not. I rely on public records or words of seller and refer to a source of  sqft. The appraiser will measure when it is time. 

Frank Rubi no - I used to do that, though....specially for room sizes. Total living area comes from public records.

Frank,
In our area it is customary to quote the County Assessor’s square footage and attribute it to them unless we or the seller feels it might be off.

We use the assessors report.

We measure our own istings.

I have a laser, which is very accurate, and I did measure my own.

I use the number in the public records. 

HECK NO!  We use the assessor provided data.  No liability that way!

I measure it myself.

Neither. 

Take it off public records

We go by courthouse records and if we want it specifically measured we pay an appraiser $100 to $150 to measure it, but only if we feel the SF is off.