Formula: °F = (°C × 9/5) + 32
Example: If °C = 25, then °F = (25 × 9/5) + 32 = 77
Quick mental check: Multiply by 2, then subtract 10% (or equivalently multiply by 1.8), then add 32
Convert using fractions: °F = (°C × 1.8) + 32
Table reference: 0°C = 32°F, 10°C = 50°F, 20°C = 68°F, 30°C = 86°F, 40°C = 104°F