Kalmaro Calc app icon

Kalmaro Calc

The everyday calculators you actually need, in one app.

Kalmaro Calc is a collection of 27 everyday calculators in one clean app for iPhone, iPad and Mac — from tips, VAT and discounts to loan, mortgage and savings repayments, room area and unit conversions, journey times and fuel costs, and quick figures like BMI. No sign-in, no clutter.

Download on the App Store

Free to download, with thirteen of the twenty-seven calculators free to use. The rest unlock together with one one-time purchase.

The Kalmaro Calc tip calculator, splitting an £85 bill four ways with a 15% tip.
  • No account, no sign-in
  • No ads, no analytics, no tracking
  • Every calculator works offline
  • A one-time purchase, not a subscription

What it does

Kalmaro Calc is one app in place of the twenty-seven you would otherwise go looking for. Every calculator in it earns its place the same way: the sum is fiddly, or easy to get wrong, or simply not something you want to be working out by hand at the time.

  1. Twenty-seven calculators, in eight groups

    The menu is the whole app — Dining & Social, Shopping, Percentages, Finance, Property, Kitchen, Travel and Health. Nothing is buried behind a mode switch or a settings screen, and the ones you reach for most can be pinned to the top of the list.

    • Thirteen are free; the rest unlock in one purchase
    • Pin the ones you use to the top of the menu
    • The same twenty-seven on iPhone, iPad and Mac
    The Kalmaro Calc menu, listing its eight categories of calculator.

  2. It answers as you type

    Each calculator is a single screen with its own number pad. There is no equals button to find and no mode to switch into — put a figure in and everything below it updates. The tip calculator will round the tip, or round the whole bill, and shows the per-person split as it goes.

    • Quick-pick chips for the usual percentages
    • Round the tip, or round the whole bill
    • A clear button on every field
    The tip calculator in the Kalmaro Calc Mac app, splitting an £85 bill four ways with a 15% tip.

  3. It gives you the verdict, not just the arithmetic

    Price Compare works out the price per unit of two things and then tells you which is better value and by how much — the answer you actually wanted, rather than two numbers to compare yourself. Discount does the same for a sale price, stacks a second discount on top, and will work backwards from what you paid.

    • Better value flagged, with the saving per item
    • Stack a second discount on top of the first
    • Work backwards from the price you actually paid
    Comparing price per unit in Kalmaro Calc, with the better-value item marked and the saving per item shown.

  4. The money ones show their working

    Loan, Mortgage and Savings give you the monthly figure and then break it apart: what you pay in total, how much of that is interest, and where the split falls. Mortgage keeps the deposit and the loan-to-value tied to each other, so moving one moves the other, and an optional overpayment shows what it saves in both interest and years.

    • Deposit and loan-to-value stay linked to each other
    • An overpayment shows what it saves in interest and in years
    • Principal and interest split out on a bar
    The loan calculator in Kalmaro Calc: monthly payment, total to be paid, and the split between principal and interest.

Calculators

Free· Unlocks with the one-time purchase

Dining & Social

  • Tip Calculator — free
  • Bill Split — requires the one-time purchase
  • Alcohol Units — requires the one-time purchase

Shopping

  • Price Compare — free
  • Discount — free
  • VAT — free

Percentages

  • Percentage — free
  • Percentage Change — free

Finance

  • Loan Calculator — free
  • Mortgage — requires the one-time purchase
  • Savings — requires the one-time purchase
  • Rent — requires the one-time purchase
  • Salary — requires the one-time purchase

Property

  • Room Area — free
  • Conversions — free
  • Paint — requires the one-time purchase
  • Tiles — requires the one-time purchase

Kitchen

  • Oven Temperatures — free
  • Volume Conversion — requires the one-time purchase

Travel

  • Journey Time — free
  • Trip Fuel Cost — requires the one-time purchase
  • Mileage Claim — requires the one-time purchase

Health

  • BMI — free
  • Water Intake — free
  • Daily Calories — requires the one-time purchase
  • Ideal Weight — requires the one-time purchase
  • Body Fat — requires the one-time purchase

Mileage Claim uses UK HMRC AMAP rates and is GBP only. The health calculators work purely from figures you type in — they’re formula calculators, not health tracking.

More screens

On iPhone · 13 screens

  • Working out a sale discount in Kalmaro Calc.
    Discount
  • The BMI calculator in Kalmaro Calc, worked out from a typed-in height and weight.
    BMI
  • Working out the fuel cost of a journey in Kalmaro Calc.
    Trip Fuel Cost
  • The alcohol units calculator in Kalmaro Calc: four pints at 5.2% totalling 11.81 units, measured against the UK weekly guideline.
    Alcohol Units
  • The mortgage calculator in Kalmaro Calc, in dark mode.
    Mortgage, in dark mode
  • The percentage calculator in Kalmaro Calc.
    Percentage
  • Settings in Kalmaro Calc: currency, the calculator the app opens on, a default tip, and the auto-save switch.
    Settings
  • An itemised bill in Kalmaro Calc, with each item assigned to the people who shared it and a total per person.
    Bill Split
  • The drinks diary in Kalmaro Calc, grouping saved days into weeks against the recommended guideline.
    Drinks diary
  • The Pinned Calculators widget on the iPhone Home Screen, listing the calculators pinned in the app.
    Pinned Calculators widget
  • The tip widget on the iPhone Home Screen.
    Tip widget
  • The oven temperatures widget on the iPhone Home Screen, converting gas marks to Fahrenheit, Celsius and fan.
    Oven Temps widget
  • The volume conversion widget on the iPhone Home Screen.
    Volume widget

On iPad · 14 screens

  • The Kalmaro Calc menu on iPad, with its eight categories.
    The menu
  • The tip calculator on iPad, splitting a bill four ways.
    Tip Calculator
  • Comparing price per unit on iPad, with the better-value item marked.
    Price Compare
  • Working out a sale discount on iPad.
    Discount
  • The BMI calculator on iPad, with its not-medical-advice note.
    BMI
  • Working out the fuel cost of a journey on iPad.
    Trip Fuel Cost
  • The loan repayment calculator on iPad.
    Loan Calculator
  • Counting alcohol units on iPad, against the UK weekly guideline.
    Alcohol Units
  • The percentage calculator on iPad.
    Percentage
  • The mortgage calculator on iPad, in dark mode.
    Mortgage, in dark mode
  • The Pinned Calculators widget on the iPad Home Screen.
    Pinned Calculators widget
  • The tip widget on the iPad Home Screen.
    Tip widget
  • The oven temperatures widget on the iPad Home Screen.
    Oven Temps widget
  • The volume conversion widget on the iPad Home Screen.
    Volume widget

On Mac · 5 screens

  • Kalmaro Calc running as a Mac app, showing the category menu.
    The menu
  • Comparing price per unit in the Mac app.
    Price Compare
  • The BMI calculator in the Mac app.
    BMI
  • Working out the fuel cost of a journey in the Mac app.
    Trip Fuel Cost
  • The mortgage calculator in the Mac app.
    Mortgage

Good to know

Do I need an account?
No. There is no sign-in, no registration and no Kalmaro account — the app works the moment you open it.
What is free, and what isn’t?
Thirteen calculators are free: Tip, Price Compare, Discount, VAT, Percentage, Percentage Change, Loan, Room Area, Conversions, Oven Temperatures, Journey Time, BMI and Water Intake. The other fourteen unlock together with one one-time purchase — not a subscription. A yearly subscription existed once; anyone who has one keeps it, and it is no longer offered.
Does it need an internet connection?
No. Every calculator works offline. The app makes one network request of its own, and it is only to ask the App Store whether a newer version exists.
Where does my calculation history go?
Onto your device. If you’re signed in to iCloud it also syncs through your own private iCloud, so your history follows you between your own devices. That happens automatically — there is no sync switch inside the app — and it can be turned off for Kalmaro Calc in your device’s own Settings, under your Apple Account → iCloud. If you’re not signed in to iCloud, the history simply stays on the device. Either way it is your storage: Kalmaro has no server and cannot see any of it.
Are the health calculators medical advice?
No. BMI, Daily Calories, Ideal Weight, Body Fat and Water Intake work purely from the figures you type in. They are formula calculators, they read nothing from Apple Health, and they are not a substitute for advice from a professional.
Which country do the money calculators assume?
VAT takes any rate you like, with quick chips for 5, 10, 15, 20 and 23%, and there is a currency setting for the rest. Mileage Claim is the deliberate exception: it applies the UK HMRC approved rates, which are set in pence per mile, so it always works in pounds.
Does it work properly on iPad and Mac?
Yes — it is a native app on all three, not a phone layout stretched to fill a bigger screen.

Getting the most out of it

  1. Pin the three or four you actually use

    The menu holds twenty-seven calculators and you probably want four of them. Pin those from the calculator’s own screen and they sit at the top of the menu — the Pinned Calculators widget shows the same list, so they are one tap away from the Home Screen too.

    A close-up of the toolbar on a Kalmaro Calc calculator screen: a history button and a pin button.

  2. Make the app open where you want it

    Settings → Default View makes any calculator the screen the app opens on. If you mostly reach for Kalmaro Calc to split a bill, there is no reason to see the menu first.

    A close-up of Kalmaro Calc’s settings: Currency set to Pounds, Default View set to BMI, and a default tip of 15%.

  3. Decide what gets kept, and name it

    Auto-Save is on by default and quietly records everything you finish. Turn it off and nothing is saved until you tap Save — where you can give the calculation a name, which is what makes it findable a month later. Either way, the clock button on a calculator shows that calculator’s own history rather than everything you have ever worked out.

    A close-up of the Auto-Save Calculations switch in Kalmaro Calc, with the note explaining that turning it off adds a Save button to each calculator.

  4. On a bill, tap who shared each item

    Bill Split is worth the extra thirty seconds. Add the items, tap who shared each one, and the tip and service charge are divided in proportion to what each person had instead of equally. That proportioning is the whole difference between it and dividing by four.

    A close-up of one item on a split bill in Kalmaro Calc, priced £32.75, with Person 1 and Person 3 ticked and Person 2 not — £16.38 each.

  5. Let Alcohol Units add up the week

    Save a day’s drinks — back-dated, if you are catching up — and the Drinks Diary groups the days into weeks and totals each week against the recommended guideline. It will also compare guidelines between countries, which sit further apart than most people expect.

    A close-up of one week in Kalmaro Calc’s drinks diary: 17.7 units against the 14-unit guideline, shown in red, with the days that made it up.

  6. Mix the units rather than converting first

    In the Travel and Property calculators each field carries its own unit, so they can be mixed freely: distance in miles with economy in L/100km and fuel priced per litre, or a room measured in feet with paint bought in litres. Nothing needs converting before you start.

    A close-up of the Trip Fuel calculator in Kalmaro Calc: distance in miles, with fuel economy switchable between mpg, US mpg, L/100km and km/L.

  7. Keep the kitchen ones on the Home Screen

    Oven Temperatures and Volume Conversion both exist as widgets, alongside Tip. Gas mark to fan oven becomes a glance rather than an app launch — which is the only way that particular conversion ever gets used.

    The Kalmaro Calc oven temperatures widget: gas marks 3, 4 and 5 against their Fahrenheit, Celsius and fan-oven equivalents, with gas mark 4 highlighted.

Get Kalmaro Calc

Twenty-seven calculators, one app, no sign-in.

Free to download, with thirteen of the twenty-seven calculators free to use. The rest unlock together with one one-time purchase.

How Kalmaro Calc handles your data →

Download on the App Store