Blog: guides and answers
43 articles answering common questions, each with a worked example and a link to the matching calculator.
Week number
- Week numbers 2027: every week at a glanceAll 2027 week numbers with the start and end date of each week (ISO 8601), plus why 1 January 2027 still falls in week 53 of 2026.
- What week number is it this week?What week number is it today? How ISO 8601 week numbers work, why 2026 has 53 weeks and how to find the week number of any date in seconds.
Dutch road tax
- How much Dutch road tax will I pay?Dutch road tax depends on weight, fuel type and province. A step-by-step guide with 2026 examples, and why one extra kilo can cost €27 more per quarter.
- How much road tax do electric cars pay?How much Dutch road tax (motorrijtuigenbelasting) does an EV pay in 2026? Examples by province and weight, the 70% rule and what changes after 2026.
- Dutch road tax: petrol vs diesel vs LPGHow much Dutch road tax do you pay in 2026 for a petrol, diesel or LPG car? A comparison with worked examples, the particulate surcharge and tips to save.
Dutch company car tax
- What does a company car cost you net per month in the Netherlands?Bijtelling isn’t an amount you pay, it’s an amount you pay tax on. How to work out the net monthly cost of a Dutch company car, with 2026 examples.
- How much company car tax will I pay on an electric car?How much bijtelling do you pay on an electric company car in the Netherlands in 2026? 18% up to €30,000, the 60-month rule, examples and net cost.
Dutch take home pay
- €50,000 a year in the Netherlands: how much is that net?On a gross salary of €50,000 a year you take home about €3,020 net per month in the Netherlands in 2026. Table from €30,000 to €100,000, explained.
- €3,000 gross a month: how much is that net in the Netherlands?On €3,000 gross a month you take home about €2,550 net in the Netherlands in 2026. The calculation, a table from €2,500 to €4,000 and payslip differences.
- How much take-home pay is 100k?On €100,000 a year in the Netherlands (incl. holiday allowance) you take home about €4,839 a month in 2026. Breakdown, tax rate and what changes it.
VAT calculator
- How to calculate VAT in the UKHow to add 20% VAT to a price and how to remove it from a VAT-inclusive price: formulas, worked examples, a table and the most common mistake.
- Dutch VAT rates: when do 21%, 9% and 0% apply?The Netherlands has three VAT (BTW) rates: 21%, 9% and 0%. Which goods and services fall under which rate, what is exempt and how to calculate with them.
Mortgage calculator
- How much does 1% on your mortgage rate cost?On a $400,000 mortgage, 1% more interest costs about $263 a month and nearly $95,000 over 30 years. How to calculate it, plus a rule of thumb.
- How much mortgage can I afford?How much you can borrow depends on income, debts, interest rate and down payment. Income multiples, the 28/36 rule and worked examples.
- What is the monthly payment on a $300,000 mortgage?A $300,000 mortgage at 6.5% over 30 years costs about $1,896 a month in principal and interest. Tables for 15 and 30 years from 5.5% to 7.5%.
Age calculator
- How old am I? Age by birth year in 2026How old are you in 2026 if you were born in 1980, 1990 or 2000? A table of ages by birth year and the simple rule to work it out.
- How to calculate how many days old you areFind out how many days, weeks and months old you are, how leap years count and when you turn 10,000 days old. With examples and a simple formula.
Compound interest
- How long does it take to double your money? The rule of 72The rule of 72 tells you in seconds how long it takes to double your money. Explanation, a table with exact values and how inflation halves your money.
- How to calculate compound interest with monthly contributionsCompound interest means earning interest on interest you already received. Explanation, formula and examples with $10,000 and $200 a month.
Loan calculator
- How to calculate loan payments with interestA $10,000 personal loan at 8% APR over 5 years costs about $203 a month and $2,166 in interest. Tables by term and rate, and tips to borrow for less.
- What is APR, and how is it different from the interest rate?APR shows the yearly cost of a loan including fees. How APR differs from the interest rate and the effective annual rate, with a $10,000 loan example.
Currency converter
- Paying by card abroad: which exchange rate do you get?Paying or withdrawing cash abroad, you don't get the rate from the news. How foreign transaction fees, ATM fees and dynamic currency conversion work.
- How to calculate exchange rates manuallyHow to convert currencies by hand with direct and inverse rates, cross rates and spotting hidden markups, with a euro–dollar table based on the ECB rate.