Commuting by bike -calories burned

[ThingsThatGoHumpInTheNight]

I started commuting by bike this week. It's 9.4 miles each way, about 4 miles on road, 5 miles on canal paths. The road section has some serious hills (make feel like you are going to be sick type hills, getting on for 15% incline). Its taking me about 55 minutes each way. I weigh about 9st7lb. MFP reckons I burn 450 calories each way, but mapmyride says about 290...which is right?

I find MFP really inaccurate at calculating calories burned. Can you use an app like runkeeper to get another estimate? That takes elevation into consideration, and also your weight etc. You can use it for cycling and walking, it's not just for running.