How it works
Each monthly payment is discounted back to today at the return you could earn on the lump sum; their total, up to the age you plan to, is what the pension is worth today. If it's more than the lump sum, the pension is the better deal at that return and lifespan. The return the pension pays is the rate at which the two are equal. In the example, $2,000 a month from 65 against $300,000 at 62 is worth $298,834 at 5% to age 90, so the two are within $1,166; the pension pays 1.77% a year if you live to 80 and 6.00% if you live to 100. More in the pension lump sum guide.