Explore General calculators and related business decision models on Martzine.
General collects closely related calculations so you can move between specific models without returning to the top-level library.
These pages cover narrower General questions and are intended to be opened when the standard calculator is not specific enough for the task.
Use the individual page for the formula, working inputs, examples, limitations and related long tail explanations.
Open the calculator that matches the decision you are reviewing. Focused sub-calculators are included where the broader model has a recurring narrower question.
Freelance Day Rate uses target annual income, billable days per year.
Freelance Project Pricing uses estimated hours, target hourly rate, risk buffer (%).
Roof Rafter Length uses rise, run.
Roof Replacement Cost uses measured roof area (ft²), cost per roofing square (100 ft²).
Roof Rise and Run uses rise, run.
Roof Square Footage uses length, width.
Take Home Pay uses gross salary, tax and withholding (%), other deductions.
Martzine’s editorial work is led by Bilal Ahmad, founder of Martzine, with support from his team across content, research and technical development. Team members contribute according to the subject and assigned work, from practical explanations and source research to tool functionality and website improvements.
Martzine publishes and maintains the tools, calculators, references, resources and articles on this website. Our editorial work covers clear instructions, calculation assumptions, useful sources and corrections when an issue is identified.
A result depends on the inputs and the limits described on its page. If you notice a calculation error, broken feature, unclear explanation or information that needs correction, please send us the page link, the details and any supporting reference. We will assess the report and correct confirmed issues as soon as practical.
Tell us what you are trying to build, what problem you are solving and where the digital part becomes difficult. Martzine is built around that gap. Start with the outcome and the constraint, then work back to the right digital layer.
