GravMass Vs TimeDilation

Hi Spacers. I write scifi thus I research science.

QUESTION TIME 

As there is no easily available cohesive, layman’s terms about this in Google. 

How Gravitational Density affects Time-Dilation. 

Planetary density is easy enough. 

Earth is 1, Mars is 0.4, we are immobilised by 4-5 and crushed by anything much higher. 

We would move slower at 2 but not because of time-dilation, it’s because our bodies muscles and bone structures adapted to 1. 

THE BIG QUESTION 

How do I calculate time-dilation for my space-ship travellers, based on knowing the planets density? 

What is the ratio? 

Internet knowledge base has failed to answer. It says ‘a third factor is required, the speed of the observer/traveller, because it’s relative.” 

That doesn’t answer my question at all. 

My space travellers are capable of standing still on the planets surface, they have teleporters to get there. 

Their spaceships have an unlimited-energy source to break away from planetary mass. Necessary technologies. 

(Their antagonists have a phase-shift tech to dismiss the effects of physical and therefore also time-dilation, because the two are intrinsically linked (does mass create time or does time create mass?) But all that comes later.)

I need to know the equation for mass-density vs time-dilation. 

Gratitude to anyone who can help with this!! 

Also: Is ‘gravity’ the same thing as Mass or is there an equation to work out the difference? 

I am using that Earth=1 Mars=0.4 both for ‘gravs’ and ‘mass’, as the Space Travellers refer to it. 

I suspect digging to get to the bottom of this will reveal two sets of observation are occurring; that the maths involved in ‘time-dilation vs gravitational mass’ will relate to the maths involving red-shift. Has anyone put those two fields into one equation? In layman’s terms.

Most people living in Space-pods don’t give a blue monkey about the maths and physics. 

They want to know stuff like:

If they take a week holiday visiting the galaxies most spectacular slow-motion waterfall planet, how much will their folks back home age in that time.

What circuit of planet-hopping grants longevity compared to the rise and fall of empires on the G2 worlds.