How many H1 tag can we use ?

[Nomanharoon]

How many <H1> can we use in a single page's body text content?

[Kevin H]

You can have as many H1 as make sense; but most people would stick to 1.

Here is what Matt Cutts has to say about it
http://www.youtube.com/watch?v=GIn5qJKU8VM

[arjun15]

hi, you have to use one according to your content information 2 and words.

[Test-ok]

H tags are for heading. Meaning your going to have content following the heading tag about the words you put in the tag.

example:
If you page is about Bricks
H1- Bricks
---H2- Types of bricks
-----H3- Sand Bricks
-----H3- Clay Bricks
--------H4- Colors
---H2- Materials Bricks are made of
-----H3- Sand Bricks
-----H3- Clay Bricks
--------H4- colors
kind of a poor example, but you should get the jest of it.

To answer your question you can use as as many as you want.
Others may disagree but I would suggest 1 <H1 tag per page.