SOD'S LAW = ((U+C+I) x (10-S))/20 x A x 1/(1-sin(F/10)).
1 First rate the urgency (U), importance (I) and complexity (C) of the task on a scale of 1 to 9 and add together 2 Rate from 1 to 9 how skilled you are at the task, then subtract this from 10 3 Multiply your answers from step 1 and step 2 together and divide by 20 4 Rate from 1 to 9 how frequently you perform the task and divide this by 10 5 Take the sine of your answer to step 4 (indicated by 'sin' on most calculators) and subtract this from 1 6 Divide 1 by your answer to step 5. Then multiply your answer to step 3 by 0.7 and multiply this by your answer to step 6
IT'S not a myth after all - Sod's Law is more than just coincidence, according to experts.
And what's more, they say, it can be summed up in the mathematical formula ((U+C+I) x (10-S))/20 x A x 1/(1-sin(F/10)).
We all know the common definition: the phone rings when you're in the bath ... your toast always falls butter-side down.
But the Sod's Law equation goes further revealing that when something goes wrong it chooses the worst moment to do so.
Thus, the shower does not run cold at first but waits until you are covered in soap, and the heating boiler will always break down at the start of a cold snap.
The formula was arrived at by an economist, a psychologist and a mathematician who looked at the Sod's Law experiences of 1,000 people for British Gas.
It includes five factors relating to any event or action: urgency (U), complexity (C), importance (I), skill (S) and frequency (F).
Apply a score of between one and nine to each, include a 0.7 factor for aggravation (A), and use the equation to find a Sod's Law rating of between 0 and 10. The higher the number the more likely Sod's Law, and therefore disaster, will occur.
Anne Morton, of British Gas, said: "In our experts' tests, the mercilessness of Sod's Law emerged. Not only do things go wrong, they do so when they are most likely to drive their victims up the wall."
The energy supplier found the most likely Sod's Law event to happen was spilling a drink down a new shirt before meeting a first date (8.5).
Others included your boiler breaking down in cold weather (8.2), rush hour traffic being worse when you are late (7.3), email crashing as you send an important document (7.0) and the washing machine breaking down before a holiday (6.7).
Psychologist Dr David Lewis said: "To decrease the chance of Sod's Law applying, you have to change one of the elements of the equation.
"If you haven't got the skill to do something important, leave it alone. If something is urgent or complex, find a simpler way of doing it.
"If something going wrong will particularly aggravate you, make certain you know how to do it."
THEORY: Toast will always fall butter-side down, says Sod's Law