SERVICE
Custom tools and calculators for businesses
I build tools tailored to a specific business process: pricing calculators, financial models, offer generators and spreadsheets that calculate what you now work out by hand. Usually in the Excel your team already knows — and in Python when more is needed.
You work directly with me · Warsaw, Poland · working remotely across the EU
Tools: Excel, Power Query, VBA, Python
What you get
- A finished tool or calculator tailored to your process
- A description of the calculation rules and assumptions
- Instructions for use and updates
- An online walkthrough and 30 days of support
- Typical turnaround
- 2–5 business days
- Quote
- free, no obligation
- Payment
- after acceptance on a first order
When I can help
- You calculate customer quotes by hand across several spreadsheets, and something always needs fixing.
- You prepare offers by copying an old file and changing the numbers — mistakes are easy.
- Several people do the same calculations (margin, discount, cost, schedule), each slightly differently.
- You need a simple financial model to check whether a venture will pay off.
- You have a spreadsheet that works, but only its author knows how to use it.
What you gain
- One tool instead of several files: enter the inputs, get the result.
- Fewer mistakes — calculation rules are written down once and tested.
- Everyone on the team calculates the same way, and faster.
- The tool stays with you, with instructions and a description of the logic.
What I do
- I walk through how you calculate today and write down the rules: inputs, calculations, output.
- I design a simple layout: fields to fill in, data validation and a clear result.
- I build the tool in Excel (formulas, Power Query, VBA if needed) or in Python when Excel isn’t enough.
- I test it on several real cases and compare the results with your existing calculations.
- I document the calculation logic so it can be changed without my help.
How I approach it
I start with how you calculate today, not with technology. If a well-built spreadsheet is enough, I won’t write an application. First I write down the calculation rules and check them with you on a few recent cases — only then do I build the tool. That way the results match what you know, and any differences are explained. An example of such a tool is the manual-work cost calculator on the report automation page.
COST CALCULATOR
How much does a manual report cost?
Enter the time your team spends on one repetitive task. The result shows the yearly cost of doing it by hand.
The hourly cost is an example — enter your own. The quote for automating the task is free.
Get a free quoteWhat I need for a quote
- What the tool is for and who will use it
- How you calculate today: a sample file or a description of the steps (no confidential data)
- Which inputs are needed and what the output should be
- Your Excel version or preferred environment
Questions
Excel or a separate application?
Usually Excel — your team knows it and no new licences are needed. I choose Python when calculations are complex, data is large or the tool should run automatically. I explain the choice in the quote.
Can you tidy up an existing calculator?
Yes. I often start by reviewing the existing file: I describe how it calculates, fix errors and simplify it. It’s a good way to start working together.
Who owns the tool?
Once the order is paid, the copyright to the files and code passes to you. The handover terms are set out in the order.
What happens after the 30 days of support?
After the 30 days I quote small fixes separately, always before starting, or we agree ongoing support. The documentation also lets someone else take the solution over.
How do we work together, and how does billing work?
You describe the problem in a few sentences. Within 1 business day I reply with questions or a proposal, then send a free quote with the scope, timeline and price. I bill through Useme, a Polish freelance platform: you get a VAT invoice, and your payment can be held by Useme until you accept the work. An NDA is available on request.
CONTACT
Tell me what you need.
A few sentences are enough. I’ll reply within 1 business day with questions or a proposed scope, timeline and price.
- No files and no tool names needed at this stage.
- Scope, timeline and price are agreed before I start.
Prefer to email? [email protected]