I would like to know the percentage of tax I will have to pay if I sell my investment property and make a capital gain. Also if I sell my investment property and then purchase another investment property (about the same price as the selling property) during the same year, would the tax situation be different?
The tax rate will depend on your total income from all sources.
If you do a 1031 exchange, and exchange one investment property for another, you can defer any gains until you sell the replacement property.
1031 exchanges have to be set up prior to selling the investment property and all monies get put into an escrow account to pay for the replacement property...be sure to let your realtor and title company know if you are considering a 1031 exchange.