Because these two terms measure two different aspects of electricity, it is not possible to convert between the two. Amperage is a measure of current flow past a given point, while voltage is the potential for current flow.
If electricity were water, the water meter on a house would show a measure of current or amperes (amps), which is the rate at which water flows into a house. If the water came from a tank high above ground, it would have more potential to flow than water from a lower tank. That potential to flow is voltage, measured in volts.