Free calculators
Four calculators you can use right away. No account, no fuss — the answer appears as you type.
VAT calculator
From an amount excluding VAT to including VAT, and back again.
Hourly rate calculator
What do you need to charge per hour to make ends meet?
Gross-to-net calculator
What do you keep from your revenue as a freelancer?
KOR check
Can you use the Dutch small business scheme, and is it a good idea?
Done calculating? Start invoicing.
Katsjing works out the VAT, your costs and your tax return for you. Start free, no credit card needed.
Start for free