Enter price, coupon and maturity: we compute gross, net and — rare among tools — inflation-adjusted yield, plus duration. For fixed-rate and zero-coupon bonds.
Yield to maturity depends on the price and the settlement date: change the price, the yield changes. To compare with another source, use the same price. One detail to watch: many sources publish the yield computed on the previous day's reference price, not on the last traded price. If you compare our yield on the last price with their yield on yesterday's reference, you'll see a few basis points of difference — that's not an error, it's the price having moved in between. At the same price, the numbers match.