Compendium of Physical Activities

The Compendium of Physical Activities Tracking Guide metabolic equivalent (MET), a standard resting metabolic rate is 1.0 (4.184 kJ) per kg per hour,
Integrity of science: driving vs walking calculations

calories expended for physical activity

Runner's World Calorie Calculator
Advanced Calorie Estimation

Calories per kg per minute per km/hour
Running    0.01713324
Cycling  0.00653064
Walking  0.01330104

walking 
17151 2.0 less than 2.0 mph
17152 2.5 2.0 mph 1.25 calorie / kg / mile
17170 3.0 2.5 mph 1.2
17190 3.3 3.0 mph 1.1
17200 3.8 3.5 mph 1.1
17220 5.0 4.0 mph 1.25
17230 6.3 4.5 mph 1.4
17231 8.0 5.0 mph 1.6

running at 1 calorie / kg / km
12030  8.0  5   mph (12 min/mile)
12040  9.0  5.2 mph (11.5 min/mile)
12050 10.0  6   mph (10 min/mile)
12060 11.0  6.7 mph (9 min/mile)
12070 11.5  7   mph (8.5 min/mile)
12080 12.5  7.5 mph (8 min/mile)
12090 13.5  8   mph (7.5 min/mile)
12100 14.0  8.6 mph (7 min/mile)
12110 15.0  9   mph (6.5 min/mile)
12120 16.0 10   mph (6 min/mile)
12130 18.0 10.9 mph (5.5 min/mile)