Measuring Body Fat

There a lots of tools online to help calculate body fat percentage. Here are a few:

http://www.fat2fitradio.com/tools/
http://www.healthcentral.com/cholesterol/home-body-fat-test-2774-143.html

My own limited experience with the scales is that they are pretty inaccurate. I got similar readings from body measurement tools online and a hand-held monitor, and on the same day got a body fat reading from a scale that was 10 percentage points off.

Short of a dunk test, my understanding is that calipers are supposed to be most accurate. I think proper training is essential for this. I bought some and failed to get an accurate reading so many times that I gave up. The Myotape that came free with my calipers is awesome, though, and totally worth $6 if you plan to do a lot of measuring.
http://www.amazon.com/AccuFitness-MT05-MyoTape-Body-Measure/dp/B000G7YW7Y

Based on the research I've done, electrical impedance is the best way to go.

I looked at calipers and the conclusion is if you don't know how to use them correctly, they are not accurate because you have to measure the same spots time after time. Based on the reading I did, this is especially true if you are trying to use them on yourself.

Omron makes good products. I opted to get a the HBF-514 scale and body fat monitor. I was within 3% of what a personal trainer calculated for me using calipers so I feel comfortable that it is relatively accurate.

Where the electrical impedance devices don't do well is if you are athletic. If you're athletic, then you need to get a device that allows you to select that feature - the Omron handheld device has this feature.

I'd say calipers. But you have to have a nurse, doctor, or other trained person do it. I have a bodyfat scale that is completely inaccurate for the reason mentioned above. It doesn't know the difference between muscle and fat. I read a lot about them and it seems they perform a calculation that involves your weight, height, and some measure of impedence. The scales only measure your lower body. If you are at all muscular, you won't get an accurate reading. I've lost 20 lb since I got the scale, yet the bf % reading has gone up. Calipers (done by doctor) put me around 23%. The scale says 38.
None of the online calculators are going to be accurate for everyone. How could they be? We are all different . I think the only way to know for sure is to get dunked. I've thought about doing that, but in the end decided to just go with how I feel, look, and how the clothes fit. That's what really matters to me anyway.