How much sq mt is 800 x 800 mm?

To convert square millimeters to square meters, you need to divide by 1,000,000. So, 800 mm x 800 mm = 640,000 square millimeters. Dividing this by 1,000,000 gives you 0.64 square meters. Therefore, 800 x 800 mm is equal to 0.64 square meters.