# Simulation of newtonian planets [duplicate]

I am creating a simulation of planets with the help of newton's law(here) and everything works fine but I can't find any source how to calculate the perfect start velocity of a planet in order to orbit another planet in a perfect circular motion given following known parameters of both planets: mass, distance from mass center to mass center, G

following code to calculate acceleration:

calcBodyAcceleration(body1, body2) {

var G = Settings.get("G");
var mults = Settings.get("multipliers");

var subtraction = Vec2.subtract(pos1, pos2);
var dist2 = subtraction.magnitudeSq();
var dist = Math.sqrt(dist2);

var mass1 = body1.mass * mults.mass;
var mass2 = body2.mass * mults.mass;

var mass = mass1 * mass2;
var force = G * (mass / dist2);

subtraction.divide(dist).multiply(force).divide(mass1);

body1.acceleration.subtract(subtraction);

}