What size furnace should I buy?

Square Footage	Furnace BTU
1,000-1,200 sq. ft. Home	40,000 - 60,000 BTU
1,200-1,500 sq. ft. Home	60,000 BTU
1,500-1,800 sq. ft. Home	60,000 - 80,000 BTU
1,800-2,500 sq. ft. Home	80,000 - 100,000 BTU
2,500-3,500 sq. ft. Home	100,000 to 120,000 BTU