Work out what your monthly expenditures are going to be. In the UK, these would include rent and rates, probably monthly mortgage payments if you own the property in which you live, your monthly utilities (electricity, broadband, phone, TV, water, gas) and all the other things you need to pay for each month such as magazine subscriptions.<p>Do you have a car? Work out the running costs. Fuel, repairs and maintenance, insurance, car tax or whatever your country charges for annual registration.<p>Add 20% to this figure to take inflation into account.<p>Now double the running total to cover the basics of food, consumables, kitchen and bathroom supplies, soap etc.<p>Double the running total again to cover clothes, fancy gadgets and fun stuff.<p>This is still only a monthly figure. To work out a minimum amount of Fuck You Money, multiply this figure by 60 to give you the minimum that you can live on for five years without having to go and look for more money, or by 120 to allow you financial independence for 10 years.