Frequently Asked Questions
Short answers to the questions people ask most about Boomer Calc. For step-by-step explanations and worked examples, see the guide.
Is Boomer Calc free?
Yes. There is no charge, no subscription and no account. The website and the iPhone app are paid for by advertising, which is explained further down this page.
Do I need to sign up or log in?
No. Open the page or the app and start typing numbers.
Are the numbers I type sent anywhere?
No. Every calculation is done on your own device, and the numbers you enter are not sent to us or saved. The ads on the site and in the app do use a network connection, and Google's ad services may process information such as your IP address or device identifiers. Our privacy policy has the details.
Why are there ads?
Ads keep Boomer Calc free. On the website, ads appear on reading pages such as this FAQ, the guide and the about page, and not on the calculator screen itself. The iPhone app shows a banner ad from Google AdMob at the bottom of the screen.
Does the mortgage payment include taxes and insurance?
No. The result is principal and interest only. Property tax, homeowners insurance, mortgage insurance and association dues are not included, so your real monthly payment will usually be higher. The guide shows the exact formula and a worked example.
Which loan lengths can I choose?
15, 20 or 30 years. The calculator assumes a fixed interest rate for the whole loan, so it is not designed for adjustable-rate mortgages, interest-only loans or reverse mortgages.
Can I use it for a car loan or another kind of loan?
The payment formula is the same for any fixed-rate loan that is paid off in equal monthly payments. Enter the price as the “home price,” your down payment or trade-in as the down payment, and the rate. The only lengths offered are 15, 20 and 30 years, so it will not fit a typical 5-year car loan.
Why does my BMI not say whether it is healthy?
Boomer Calc shows the number only. For adults, the CDC treats 18.5 to under 25 as a healthy weight range, 25 to under 30 as overweight and 30 or more as obesity. BMI does not tell muscle from fat and is a rougher guide for older adults, so please discuss your result with your doctor rather than relying on the number alone.
Can I enter my height in feet and inches?
The imperial setting takes your height in inches only. Multiply your feet by 12 and add the extra inches: 5 feet 7 inches is 5 × 12 + 7 = 67 inches.
Why does the tip split come out a penny off?
Each person's share is rounded to the nearest cent. A $99.71 total split three ways is $33.2366…, which shows as $33.24, so the three shares add up to $99.72. Money cannot be split into fractions of a cent, so somebody rounds by a penny.
Does the sin button use degrees or radians?
Degrees. sin(30) gives 0.5 and sin(90) gives 1.
What does "Cannot divide by zero" mean?
A number divided by zero has no answer, so the calculator stops and tells you rather than showing a misleading result. Press C and try again.
Is there an iPhone app?
Yes. Boomer Calc is also built as an iPhone and iPad app with the same four calculators. It needs iOS 14 or later. You can also add the website to your home screen: in Safari, tap Share, then “Add to Home Screen.”
The text is too small for me. What can I do?
On a computer, hold Ctrl (Command on a Mac) and press + to zoom in. On an iPhone or iPad, go to Settings → Accessibility → Zoom, or Settings → Display & Brightness → Text Size.
I found a mistake. How do I report it?
Email steveabramsdesigns@gmail.com with the numbers you entered, what you expected and what the calculator showed.