How much should I spend on an engagement ring if I make 100k?

The old idea of two months' salary is a guide, not a law. What matters is what you can afford without stretching your budget or taking on debt. Think about your joint goals, such as a house deposit, holidays or starting a family, and let those shape your choice. Some people prefer a modest ring and put the rest toward a wedding day they will remember. Others choose a larger stone because it holds sentimental value. Look at your take-home pay after tax, pension and other outgoings, then decide how much you can set aside without affecting your monthly bills. Remember that the ring is a symbol, not a measure of love, and the person you are asking will care far more about your honesty and thoughtfulness than the price tag.