Could someone help me find a math equation?

Believe it or not, the system we have in place (the House of Representatives) pretty much handles that already. A direct democracy would be cumbersome and even less effective than what we have right now (do you want to spend all of your free time voting on hundreds or thousands of bills per year? Now, do you think other people want to spend their time doing the same?).

There are 435 representatives in the House.
Each district has an average of 711,000 people in it.
The largest district has 994,000 people in it (Montana)
The smallest district has 527,000 people in it (Rhode Island)

http://demography.cpc.unc.edu/2016/02/29/u-s-congressional-district-population-estimates-and-deviation-from-ideal-population-size-2014/

They claim that roughly 3/4 of the districts aren't distributed ideally, but if you look at their criteria, they claim that anything outside of the ideal is anything that's more than 0.5% from ideal (+/- 3600 people from 711,000, roughly).

https://en.wikipedia.org/wiki/List_of_United_States_congressional_districts

Let's take a state with only a couple of districts, like Idaho, and see if it's "ideal."

1st district: 649,000 people
2nd district: 645,000 people

Both of these districts would be considered less than ideal because each one has a population that's far outside of the average population for each district in the USA, but is there really a better way to divide it up? Not really. Dividing it even more would just increase the representative power of each voter in each district, especially when compared to voters in other states. Cutting it down to one statewide district would dilute the representative power of each voter in Idaho.

However, there are solutions that we aren't considering:

1) No more voting along state lines. For instance, in Idaho, if District 1 overwhelmingly supports a bill (let's say all 649K people in District 1 support a bill) and District 2 overwhelmingly does not support the bill (all of the people vote against it), then the bill shouldn't receive both votes, just because statewide, the majority of the people support it. It should get 1 vote for and 1 vote against, plain and simple.

2) Increase the number of representatives. Ever since the Apportionment Act of 1911, the House of Representatives has had 435 seats, and since then, representatives have had to represent more and more people. Do you think a representative can truly gauge or serve the will and needs of 711,000 constituents? No, of course not. But what if a representative only represented, at most, 50,000 people? That'd be a lot better, don't you think?

3) Insist on shorter terms for all political offices or insist on term limits for all political offices. The Consuls of Rome had a single year to enact their policies. They could get reelected, but it wasn't extraordinary to be replaced. If every member of congress and the President only had single year terms, how quickly do you think things would move? Every year, there'd be a national work release day for voting and government would have to reflect the will of the people. Place a 10-year term on members of the Supreme Court as well. Lifetime appointments are idiotic. Even the Catholic Church has an enforced age for the retirement of priests (priests must retire at 70, bishops and archbishops at 75, and only the Pope is exempt).

A direct democracy would be too slow and cumbersome, but what we have is not a representative democracy either. We need more representatives, so districts can be better suited to the needs of their resident voters.

Get the percentage of votes for Yes and No in each state.
The Yes and No percentages add up to 100% or 1.00 in each state.

Add up all the Yes and No percentages. Now they totals add up to 5000% or 50.00. Divide the sums by 50 to get the equal-weight Yes and No percentages.

All that does is to take the average of the Yes and No percentages. Add up the 50 Yes percentages, and divide by 50. Do the same for No percentages. Each state is being given equal weight, since you are just taking the plain percentages, not weight them for the size of the state.

A 50 state example is too long, so here's a 5 state example. (I'll omit the % sign.) Suppose the Yes and No percentages in the 5 states are:
45 55
40 60
50 50
60 40
52 48.

Those add up to 247 and 253.
Divide by 5 and you have the averages:
49.4% and 50.6%

Take the proportion of yes votes to the *total* votes.

For example:
In California you have 10000 yes votes out of 16000 total.
10000/16000
= 5/8
= 0.625
= 62.5% voting yes

In Maine, you have 1000 votes out of 1600 total votes.
1000/1600
= 5/8
= 0.625
= 62.5% voting yes

In general, the formula for the percentage of yes votes would be:
Y / (Y + N) * 100%

Likewise, the formula for no votes would be:
N / (Y + N) * 100%

Uh, the president doesn't make bills.

The president is the commander-in-chief of the military. He is the top cop. That's what the executive branch of government does: enforcement.

The legislative branch does the lawmaking.
The executive branch enforces the laws.
The judicial branch sorts out all the bugs.

There are no federal police.

The constitution gives the "police power" to the several states.

What is the police power? The ability to legislate (create laws), enforce the laws, and adjudicate (work out the glitches between the laws and the enforcement of the laws.

Any THING that is not a REAL or SUBSTANTIAL threat to the SAFETY, HEALTH, MORALS or WELFARE of THE PEOPLE, is NOT within the POLICE POWER.

This is CONSTITUTIONAL LAW.

As you can see, most of the USA government is operating OUTSIDE of the constitution.

My city makes it a violation of the law to have grass that is over 6 inches in length; a truly unconstitutional law. Where are we headed? Remember the U.S.S.R.?

Your question is anything but clear, but I believe you want each state (not each voter) to have the same representation. That is actually something like the Senate, not the House of Representatives. However, senators are not legally bound to the wishes or votes of their constituents. What you would need would be one vote per state, and that vote would be decided by the popular vote in each state. In this way California and Maine would have equal representation, although their voters certainly would not.

Even that would not necessarily settle the matter. Suppose that California voters were unanimously in favor (16,000 - 0), while Maine was opposed, but wavering (799 - 801). Would you wish that to count as one for and one opposed? That is not clear.

Incidentally, your aspirations to the office of President are beside the point. The system you suggest is for beyond the powers of that office.

Set up a proportion

Reduce the House to one representative per state.

Good luck with that.