Calculus is beautiful and it is absolutely necessary for all physical sciences and has serious applications for financial sectors, computer science, and many other fields as well.

However, for the average person who is not going into any technical field, probability will have a far greater impact on their day to day lives than calculus. Probability is useful for everyone in this world.

Anecdotally, I have a bachelor's in mathematics. It occurred to me several years later when I went back to start on my master's that I had virtually never used calculus after graduating and had to review a lot of my basic calculus notes.

At the high school level you don't really know what you'll be doing 15 years later? You should have a complete grounding, so that you can make those decisions and not have to play catch up later on. I am not saying probability and stats are less important (probability is as important and increasingly stats), but you need calculus as well, at least a good basic grounding.

Agreed, but that is not the question. I would love to see everyone holding a diploma walking out with some knowledge of both calculus and statistics.

The question is given limited time in school, which is more important and useful for the average person? I think the answer is statistics and probability. People confront probability and statistics in the news all the time and make practical decisions based on what they think is more likely. Most people can apply probabilities in their daily life, few people in nontechnical fields will use calculus.

I brought up my own experiences to point out that as a former military analyst and current DBA and programmer I have used basic statistical knowledge on a regular basis. I have used knowledge of Calculus so little in my daily life and job that I had to give myself a very thorough refresher when I returned to an academic study of mathematics.

As a counter point, I have a masters in math, but highschool calculus almost drove me away from math completely. It was very obtusely taught and by far the dullest course I took in highschool.

The amount of calculus you actually need for high school science is both a lot less than what is taught at high school and different calculus than is taught at high school. I agree that most of calculus should be left to university since they're going to have to re-teach most of it anyway to undo the damage done by a bad high school curriculum.