Donato De Tullio Back to the site
★ Free calculator · no email asked

The D of Data · the 5D Method

Courage doesn't pay the rent.
Numbers do.

When I was thinking about leaving everything, fear kept asking me one question, always at night. What if nothing comes in? One day I did the math, and the night went back to being a night. This calculator does that math for you: four numbers, and you know how many months you can go on if your income stops. Everything stays on your device. No email, no account.

Run the numbers 2 minutes · updates as you type

Why this number

The first D is Data.

At a crossroads the feeling always leans towards the side of fear. At night your head doesn't do the math, it makes movies. The Data of the 5D Method are there to switch off the projector: instead of "what if I don't make it" you get a number, the months your reserve keeps you standing if you stop collecting. It is the most useful fact to hold in your hand before you choose.

It's not about courage

People who don't jump are usually not cowards. They are afraid because they have never done the math underneath, and so far they are right. The number either removes the fear or confirms it. Either way, you stop being afraid in the dark.

It's not forever

A low result is not a no. It is a not yet. First you rebuild the cushion, and knowing how many months are missing is already half a plan.

The calculator

Four numbers, and you see.

Put in honest figures, even rough ones. A number inflated to feel safe works until the first bill. The result updates by itself as you type.

Rent, bills, groceries, loan payments, transport. The minimum that keeps you and your family standing, without the extras.
a month
Tools, subscriptions, a collaborator, your VAT registration. The fixed costs the project asks of you every month. If nothing is up and running yet, leave it empty.
a month
Bank account, savings account, whatever you can touch without penalties. The savings you can actually use to live on. The house and the pension fund stay out.
in total
The salary or revenue that ends up in your pocket, on average, after taxes. It powers the reduced-income scenarios.
a month
Two figures are enough to start, your living costs and your cash reserve. You can add the rest whenever you want.

Got your number?

Now let's read it together.

30 minutes, free, over a virtual coffee. You tell me your crossroads and your months of runway, and we look at the first real move. In English, Italian or German.

Let's have a coffee (30 min)

What now?

You have the Data. The rest is missing.

Not sure where to start? The Stay-or-Leave Test Ten questions to find out which of the five Ds you are really missing to decide. If it's not the D of Data, this is where you find out which one it is.
Take the test → The business tune-up More Data, about the project instead of the wallet: where your idea holds and where it creaks, before you bet the reserve on it.
Run the tune-up → The 5D Method, in full Data, Direction, Decision, Destination, Desire: the five steps explained one by one, and how they work together at a crossroads.
See the method → The minimum rate calculator The right price fills the reserve, and the reserve buys time: find the price below which you are not selling, you are paying.
Find your number →

One honest thing

It's a snapshot, not advice.

This calculator does one thing: it divides the reserve by what you spend. It knows nothing about taxes, severance pay, interest or income that swings, and it doesn't know that expenses change when life changes. It gives you a true order of magnitude to start from. It doesn't get the last word.

This is not financial advice, and I am not the person who can give you that. I have a scientist's head and my hands in operations, not an accountant's license. For taxes, investments and the numbers that really weigh, take this number to a qualified professional. This page is here to get you started with the data in hand, not to close a big decision on your own.

I stopped asking for email addresses in exchange for resources. The calculator is yours, the result too, no contact details required. If it helped, have a look at the English home, browse the book Stay or Leave?, or the full site in Italian, and we can always talk over a coffee.