How to use Do The Calculation tools, save and export your calculations, and get the most from related resources.
The Site Guides category helps you get the most out of the Do The Calculation platform. Articles cover how to use the calculator interface, save and export your results, understand the formulas behind each tool, use the site on mobile devices, and compare multiple calculation scenarios side by side. Whether you are a first-time visitor or a regular user, these guides explain the navigation, features, and best practices that make the platform more useful for your financial, health, and business planning.
Every other category on this blog explains a calculation; this one explains how to get more out of the calculators and guides themselves: finding the right tool quickly, reading a result correctly, saving a calculation you want to return to, and understanding where a calculator’s formula actually comes from.
Start here if you are new to the site rather than looking for a specific number. These articles are short by design and assume no domain knowledge. The goal is to save you time navigating, not to teach a calculation.
Articles
Where to start in site guides
If you only read one article here, start with Understanding Calculator Formulas: How DTC Turns Inputs into Results, and How to Compare Calculator Scenarios Step by Step. These cover the most common questions in this category and link to the calculator that matches.
5 articles are published in this category so far. Each one follows the same structure: the formula or method, a worked example, a comparison table where relevant, and a direct link to the live calculator.
Context
What "saved" actually means on this site
A saved calculation is stored in your own browser, not on our servers, which means it stays private to you but is also specific to that browser and device. It will not appear if you open the site in a different browser or after clearing site data. That tradeoff is deliberate: no account or signup is required for any calculator.
If you need a result to survive across devices or to share with someone else, exporting it (where a calculator supports that) or copying the figures into a spreadsheet template is more durable than relying on the saved-in-browser feature.
Scenarios
Finding the right tool fast
When you are not sure which calculator applies, start from the category hub closest to your question rather than searching by exact tool name. Hubs group related calculators together and usually surface the broadest, most-used tool first, which is a reasonable starting point even if a more specific tool ends up being the better fit.
For comparing scenarios (two loan offers, two pricing options), running each one through the same calculator separately and recording both results somewhere (a saved run, a note, or a template) is more reliable than trying to hold both sets of numbers in your head while switching inputs back and forth.
Comparison
Quick estimate versus step-by-step method
Some calculators on this site show only the final result; others show the full step-by-step working behind it. Use the quick-result view when you already trust the method and just need the number; use the step-by-step view when you are learning the calculation, checking your own manual work, or need to explain the answer to someone else.
The "Understanding Calculator Formulas" guide is the one to read if a result surprises you and you want to know exactly which formula produced it rather than treating the tool as a black box.
Limits
What site guides do not cover
These articles describe how the site currently works, and features can change between updates. If a guide describes a save or export behavior that does not match what you see on the page, the live calculator page is the current source of truth, not the article.
Site guides do not explain the domain-specific formulas themselves in depth; for that, the category-specific guide attached to the calculator you are using is the right place to look.
FAQ
Frequently asked questions
What do the site guides guides cover?
These guides explain how to find the right calculator, read and save a result, and understand where a calculator formula comes from. Each one walks through the formula, a worked example, and links to the matching calculator so you can apply the method to your own numbers.
Which site guides guide should I read first?
Start with the article closest to your immediate question. Common starting points in this category include How to Use Do The Calculation Calculators: A Practical Step-by-Step Guide, Saving and Exporting Calculations: How to Keep and Reuse Your Results, Understanding Calculator Formulas: How DTC Turns Inputs into Results, Using Do The Calculation on Mobile: Practical Guide, and How to Compare Calculator Scenarios Step by Step. If you are not sure, start with the broadest one and use its links to reach a more specific guide.
Are the site guides guides and calculators free to use?
Yes. Every guide, calculator, and template on Do The Calculation is free, with no account or signup required.
What should I have ready before reading one of these guides?
It helps to have nothing beyond the calculator or feature you are trying to use: these guides explain the site itself, not a domain-specific formula on hand, since the guide’s worked example uses illustrative numbers and the value is in matching its method to your own figures.
How accurate is the information in these guides?
The guides use published, standard methods, and each one states its assumptions so you can check the working rather than take the output on trust. Site guides describe how Do The Calculation works. Features and saved-data behavior can change between updates; the calculator page itself is the current source of truth.
What is the most common way to misread one of these guides?
The most common mistake in this category is assuming a saved calculation is stored on our servers, when it is actually kept in your own browser and tied to that browser and device. Reading the worked example carefully before applying it to your own numbers usually catches this.
Can I compare more than one scenario using these guides?
Yes. Run the matching calculator once for a baseline, change one input, and run it again. Useful angles to compare in this category include browser-local save vs exported file, single scenario vs multiple saved runs, and quick estimate vs step-by-step method view.
How do the guides relate to the calculators?
The calculator gives you the answer; the guide explains how that answer was reached and what to do with it. Every guide links to its matching tool, and the tool links back to its guide.
Which articles are most popular in site guides?
Featured articles in this category include Understanding Calculator Formulas: How DTC Turns Inputs into Results, and How to Compare Calculator Scenarios Step by Step.
How often is this content updated?
Articles are revised when the underlying method, published guidance, or the matching calculator changes. Each article shows its published and last-updated date so you can judge how current it is.
Can I use these guides and calculators on mobile?
Yes. Every guide and calculator page is designed to work on mobile, tablet, and desktop screens.
What should I do with the result after reading a guide?
Turn it into a next action: use the site itself more efficiently: finding tools faster, saving results you want to keep, and knowing how much to trust a given output. That is the intended outcome of pairing a written guide with a live calculator instead of publishing either one alone.