Gear Ratio for BMX Bike for street and dirt?

How many teeth will i need on my front sprocket and my back sprocket for a street and dirt gear ratio

Most street, park and dirt riders ride all three surfaces and desire smaller gears to simulate a gearing similar to BMX gearing. The small gears have less chance of bending or breaking when practicing tricks as well as less surface area of dangerous pointed chainwheels if and when a trick goes awry. Typically these riders use what are called "lo-lo" gears with a small 25 to 28 tooth chainwheel up front paired with a 9 tooth cog in the rear. A 26/9 combination results in a 56.33 gear ratio.