You can go on IRC https://kiwiirc.com/client (it is actually available from the pool on http://monero.crypto-pool.fr/#community )
Channel #monero (type "/join #monero" to join)
In the chat, type "!calc 1270" (you must type the average hashrate reported by the pool, not the hash from the miner)
But the bot that calculate is down at the moment. You must wait for the admin (not me) to restart it.

Note that it is only an estimate. If the global hashrate increase during the day, you'll get less than expected because of the competition .
It is actually increasing a lot these days as the price increase.