Word count question

[klwilliams]

For me, proper manuscript format for submitting for publication is Courier font, 12 point, double spaced. The word count is 250 words per page, or ten words per line. My question, though, is that these days the word processor will count the number of actual words. For print magazines, my understanding is that what matters is how much space is filled rather than how many actual words there are, which is where the 250/page came from. Is this still true, or should I claim the number of actual words when submitting? (I'm not worried about payment. As usual, I just don't want to appear stupid.)