how far away is mars in meters

Mars is currently about 2.4 to 2.5 astronomical units away from Earth on average, which translates to roughly 225 million kilometers or 225,000,000,000 meters. The distance fluctuates as both planets orbit the Sun, ranging from about 54.6 million kilometers at closest approach to about 401 million kilometers at maximum separation. In meters, that corresponds to about 5.46×10^10 m at closest approach and up to about 4.01×10^11 m at greatest separation, with an average around 2.25×10^11 m. These figures depend on the instantaneous positions in their orbits, so the exact distance just now can differ. If you’d like, I can estimate the current distance in meters for your location using an ephemeris.