Hi sparklykid, the charge daily is big but it's a constant, so you simply add both gas and elec standing charges together, multiply by 365 days. Then look at your bill to see your usual usage of kwh of gas (PER YEAR!), multiply that by the new tariff's kwh rate for gas, then do the same for the electric, then add all 3 results together. I done this for many fixed tariffs. It works better for me at the moment and should beat the variable tariff hikes that are at 50%+. If you use less energy than I do, it may not be for you as the standing charge could be too big a proportion of your bill.
Over the next month or so, we'll see all sorts of tariffs appear so if any are less, I can switch penalty free from Eon v10. The tariffs are designed to blind you with numbers and trick you.
Another thing is, Eon have delayed the switch for me until April 1st so I'm still on the lower variable until then.
Have a go at the calculations, hope you find a good result.