In reply to UKH Articles:
Running with no sense of how long it's going to take can be grand. But if you do need to assess likely time (eg to tell your partner when you're likely to be back), the Naismith formula converts to 100m of ascent counts as 0.8km extra. Then reckon in your hill speed, likely to be about half your road speed, but experience will soon give a figure for it. In my running days I used to reckon 6.5 km/hr (ie after adding in the allowance for the ascents) for long outings.