Transformer - 25%?

Hi -
We are moving to London at the end of May for approximately two years.  Rather than buying all new kitchen appliances, we decided to move the appliances we really need and bought the appropriate transformer.  I spoke with a gentleman at www.BuyUnderCost.com who said your transformer should accomodate the total watts plus 25%.  So, if I have an appliance that is 1000 watts, I need a 1250W transformer.

Well.....after buying and shipping our 1500W transformer to London, I realized our toaster oven is 1500W.  :-/ From your experience, will the transformer work for the toaster oven or do I really need the extra 25%?
Thanks!
Carrie

The "extra" 25% is for the start-up spike that some appliances draw, but it is only really an issue for appliances with motors - until the motor gets spinning.  

Appliances that draw a current for heating purposes only probably don't need the extra 25%, but if you are bringing a quality hi-fi then you should allow more as a stereo amplifier may draw peak current much higher than its rated power.  I run my component hi-fi system off a 2KW transformer when its rated power consumption would be less than 250W even if I ran the amplifier flat-out.