This question is hard to answer because it depends on a lot of factors such as what phone model is being charged, if a quick charge adapter is being used, how old or new the phone itself is, whether the phone is in use at all during charging and even the position of the phone on the charger. Wireless charging is quite different from wired charging.
As a general rule of thumb, wireless charging is slower than wired charging although it offers greater convenience and aesthetics. As a standard, an iPhone X can take 3 hours to obtain full charging using a wireless charging pad. A Samsung S8 will gain a full charge a bit quicker at 1 hour and 40 minutes to fully charge.