The norm on engagement rings is to spend 20 percent of your annual gross income. How ever there is always other factors to consider since you are buying something that not only will it last forever but will remain in her heart for the rest of her life. Another factor you should consider is that is she really the one? I remember my first engagement as well as my second, the second was a lot easier since I knew what to expect. The easiest way to decide is to really find out what styles and cuts she likes by asking her friends, they would be more than happy to help but do not let them intrude too much if you know what i mean. another factor to consider is what can you really afford? I know some people that only make minimum wage and that barely gets them any decent diamond ring. Knowing ahead of time these and do not forget to take into consideration what she brings to the table. That is a big factor in knowing if you are just going to spend just the 20 percent of your annual gross income or if you will spend more than the 20 percent of your annual gross income. So in order to calculate what to spend for an engagement ring always consider that the expected amount is 20 percent of your annual gross income and I would add another 10 percent to that if she really and truly deserves it.  The norm on engagement rings is to spend 20 percent of your annual gross income. How ever there is always other factors to consider since you are buyi…