Free calculators for your firm's website

Give visitors to your firm's or association's website tools they use every day: due dates, late-payment interest, withholding tax, VAT, margins. They are free, update themselves (for example each half-year's late-payment rate) and adapt to phones.

How to add them

Pick a calculator and press Copy the code.
Paste it into the page of your site where you want it, as an HTML block (in WordPress: the "Custom HTML" block).
Done: the calculator adapts its height and width.

Available calculators

Invoice due date calculator

30, 60, 90 days from invoice date or end of month, with a fixed day.

<iframe src="https://www.cassachiara.com/en/invoice-due-date-calculator.html?embed=1" title="Invoice due date calculator" style="width:100%;max-width:760px;height:820px;border:0" loading="lazy"></iframe>
<script>addEventListener('message',function(e){if(e.origin==='https://www.cassachiara.com'&&e.data&&e.data.ccH)document.querySelectorAll('iframe').forEach(function(f){if(f.contentWindow===e.source)f.style.height=e.data.ccH+'px'})})</script>

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Late-payment interest calculator

Italian statutory interest half-year by half-year, plus the €40 flat fee.

<iframe src="https://www.cassachiara.com/en/late-payment-interest-calculator.html?embed=1" title="Late-payment interest calculator" style="width:100%;max-width:760px;height:820px;border:0" loading="lazy"></iframe>
<script>addEventListener('message',function(e){if(e.origin==='https://www.cassachiara.com'&&e.data&&e.data.ccH)document.querySelectorAll('iframe').forEach(function(f){if(f.contentWindow===e.source)f.style.height=e.data.ccH+'px'})})</script>

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Italian withholding tax calculator

Freelance invoice from gross to net and back.

<iframe src="https://www.cassachiara.com/en/withholding-tax-calculator.html?embed=1" title="Italian withholding tax calculator" style="width:100%;max-width:760px;height:820px;border:0" loading="lazy"></iframe>
<script>addEventListener('message',function(e){if(e.origin==='https://www.cassachiara.com'&&e.data&&e.data.ccH)document.querySelectorAll('iframe').forEach(function(f){if(f.contentWindow===e.source)f.style.height=e.data.ccH+'px'})})</script>

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Italian VAT calculator

Net amount and VAT at 22%, 10%, 5% and 4%.

<iframe src="https://www.cassachiara.com/en/italian-vat-calculator.html?embed=1" title="Italian VAT calculator" style="width:100%;max-width:760px;height:820px;border:0" loading="lazy"></iframe>
<script>addEventListener('message',function(e){if(e.origin==='https://www.cassachiara.com'&&e.data&&e.data.ccH)document.querySelectorAll('iframe').forEach(function(f){if(f.contentWindow===e.source)f.style.height=e.data.ccH+'px'})})</script>

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Margin and markup calculator

Percentages and the selling price for a target margin.

<iframe src="https://www.cassachiara.com/en/margin-markup-calculator.html?embed=1" title="Margin and markup calculator" style="width:100%;max-width:760px;height:820px;border:0" loading="lazy"></iframe>
<script>addEventListener('message',function(e){if(e.origin==='https://www.cassachiara.com'&&e.data&&e.data.ccH)document.querySelectorAll('iframe').forEach(function(f){if(f.contentWindow===e.source)f.style.height=e.data.ccH+'px'})})</script>

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DSO calculator

How long clients take to pay and how much cash is tied up.

<iframe src="https://www.cassachiara.com/en/dso-calculator.html?embed=1" title="DSO calculator" style="width:100%;max-width:760px;height:820px;border:0" loading="lazy"></iframe>
<script>addEventListener('message',function(e){if(e.origin==='https://www.cassachiara.com'&&e.data&&e.data.ccH)document.querySelectorAll('iframe').forEach(function(f){if(f.contentWindow===e.source)f.style.height=e.data.ccH+'px'})})</script>

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What appears on your site

Only the calculator, in CassaChiara's dark colours, with a small line at the bottom crediting the source. Numbers typed by visitors stay in their browser: we collect no data and use no tracking cookies.

And for your clients?

With CassaChiara's Studio plan you manage up to 30 client companies: from their Italian e-invoices, a payment schedule, a 90-day cash forecast and a PDF report with your firm's name.

See the Studio plan Free 14-day trial

Frequently asked questions

How much does it cost?

Nothing: the calculators are free, including commercial use on a firm's or association's website.

Can they be customised?

The code works as it is. If you need a version with your firm's name, write to giuseppe@cassachiara.com.

Do they work on WordPress, Wix and similar?

Yes, anywhere you can add an HTML block: WordPress, Wix, Squarespace, Joomla and hand-made sites.

More guidesAll free toolsCassaChiara for accounting firms Download invoices from the cassetto fiscale Payment reminder templates 90-day cash-flow forecast Payment schedule from Italian e-invoices Supplier IBAN change fraud Open a P7M file online for free CassaChiara for accounting firms