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## A calculator app in Boundless

### Available for Unlimited All Access members only

Formulas (“Boundles”) in Boundless are powerful, they are like little excel cells you can use in tables or use in your website.

Boundles are also live updating, this means you can wire up formulas that update live on your website as your users enter and change data.

In this tutorial we'll show how to use Boundles to build a live updating mortgage calculator.

Define a mortgages table with the following columns:

• Amount → Money
• Interest Rate → Number (Decimal)
• Term → Single Option Select with (10, 15, 30, 40) as options
• Monthly Interest Rate → Formula (Current Mortgage.Interest Rate / 12 / 100)
• Term months → Formula (Current Mortgage.Term * 12)
• Monthly Payment → Formula FORMAT_CURRENCY(Amount * (Monthly Interest Rate * (1 + Monthly Interest Rate) ^ Term Months) / ((1 + Monthly Interest Rate) ^ Term Months - 1)

We can add a row to confirm that the formula is correct:

#### Goto the landing page /

• Hide the page footer
• Drag and drop in a form for Mortgages
• Layout the inputs by dragging them next to each other
• Add a content node under the last input
• Add a Boundle to output the Monthly Payment by typing =Current Mortgage.Monthly Payment
• Save and publish

### The full tutorial is available for pro members only

Formulas (“Boundles”) in Boundless are powerful, they are like little excel cells you can use in tables or use in your website.

Boundles are also live updating, this means you can wire up formulas that update live on your website as your users enter and change data.

In this tutorial we'll show how to use Boundles to build a live updating mortgage calculator.

Define a mortgages table with the following columns:

• Amount → Money
• Interest Rate → Number (Decimal)
• Term → Single Option Select with (10, 15, 30, 40) as options
• Monthly Interest Rate → Formula (Current Mortgage.Interest Rate / 12 / 100)
• Term months → Formula (Current Mortgage.Term * 12)
• Monthly Payment → Formula FORMAT_CURRENCY(Amount * (Monthly Interest Rate * (1 + Monthly Interest Rate) ^ Term Months) / ((1 + Monthly Interest Rate) ^ Term Months - 1)

We can add a row to confirm that the formula is correct:

#### Goto the landing page /

• Hide the page footer
• Drag and drop in a form for Mortgages
• Layout the inputs by dragging them next to each other
• Add a content node under the last input
• Add a Boundle to output the Monthly Payment by typing =Current Mortgage.Monthly Payment
• Save and publish

Formulas (“Boundles”) in Boundless are powerful, they are like little excel cells you can use in tables or use in your website.

Boundles are also live updating, this means you can wire up formulas that update live on your website as your users enter and change data.

In this tutorial we'll show how to use Boundles to build a live updating mortgage calculator.

Define a mortgages table with the following columns:

• Amount → Money
• Interest Rate → Number (Decimal)
• Term → Single Option Select with (10, 15, 30, 40) as options
• Monthly Interest Rate → Formula (Current Mortgage.Interest Rate / 12 / 100)
• Term months → Formula (Current Mortgage.Term * 12)
• Monthly Payment → Formula FORMAT_CURRENCY(Amount * (Monthly Interest Rate * (1 + Monthly Interest Rate) ^ Term Months) / ((1 + Monthly Interest Rate) ^ Term Months - 1)

We can add a row to confirm that the formula is correct: