It all depends on the STEEM Power (VESTS) and the voting power of those upvoting your posts.

I use steemstats.com by @jesta to monitor the votes on my posts. This tool shows you the impact of each vote on your posts. The tool is Google Chrome compatible.

To monitor your voting power or that of some one else, I use the steemd tool. This tool is MS IE compatible.

A person's voting power along with their amount of STEEM Power equates to an upvote impact in SBD and SP on your post.

I hope that explains it a little better for you.

Steem on,
Mike