Severance pay and tax in Germany: the one-fifth rule explained
Fully taxable but free of social contributions: how the one-fifth rule works and what changed in 2025.
Guides
Guides on taxes, finance, family and housing
Clear guides to the big money questions of everyday life — with sources, examples and direct links to the matching calculators.
A calculator gives you numbers. A guide explains what they mean — and which rules apply in the background. This page lists every guide on Ultra Calculator, sorted by topic. They range from mortgages, gross-to-net and housing benefit to the pregnancy timeline and dedicated guides for Polish workers and care workers in Germany. Every guide cites its sources, names common misconceptions and links the matching calculators so you can switch between explanation and calculation effortlessly.
21
Guides
12
Topics
10
Languages
Recommended guides
The most important explainers for money topics
- Buying property in Germany – financing, closing costs, rental yield and property tax This guide combines purchase ancillary costs, annuity financing, rental yield and the 2025 property-tax reform into a coherent view of buying and letting decisions.
- Gross and net salary in Germany – taxes, social charges and the payslip explained This guide breaks down the German payslip into its components, explains tax classes, contribution ceilings and special cases, and shows why there is no single formula for net pay.
- Understanding ETFs, savings plans and compound interest This guide explains how ETF, savings plan and compound interest calculators fit together in long-term investing.
- Citizenship allowance, housing allowance and child supplement – understanding German welfare This guide explains standard rates, rent levels, income offset logic and the interfaces between citizen benefit, housing benefit and child allowance – with worked examples and an overview of typical pitfalls.
- Working in Germany: Guide for Polish employees Gross and net, housing benefit, child benefit, child allowance, parental benefit, unemployment benefit and pension: what entitlements Polish employees have in Germany and where they can count on.
- Polish nursing staff in Germany: wages, working hours and rights Minimum wage for nursing care, working time rules, the reality of 24-hour care, the EU recognition of Polish nursing training and the difference between posting and German employment.
Salary & Taxes
Gross, net, income tax, severance, VAT
Understanding gross and net – taxes, social security contributions and the German wage system
The guide breaks down German payroll accounting into its components, explains tax classes, contribution assessment limits and special cases and shows why there is no single net formula.
VAT, discounts and cash discounts clearly explained
The guide clearly separates VAT, discounts and cash discounts, explains the mathematical basics and shows why percentage values from different steps should not be added together.
Benefits & social support
Housing benefit, parental allowance, unemployment benefit and more
Understanding citizen's benefit, housing benefit and child allowance
The guide explains standard requirements, rent levels, calculation logic and the interfaces between citizens' benefit, housing benefit and child allowance - with concrete examples and an overview of typical pitfalls.
Understanding pension, parental allowance, sickness benefit and unemployment benefit
This guide explains when pension, parental allowance, sickness benefit and unemployment benefit calculators are useful.
Working in Germany: Guide for Polish employees
Gross and net, housing benefit, child benefit, child allowance, parental benefit, unemployment benefit and pension: what entitlements Polish employees have in Germany and where they can count on.
Investing & Finance
ETF, savings plan, loans, instalments and interest
Overdraft interest in Germany explained: calculate the cost and save
Daily interest, tolerated overdrafts and refinancing: how to cut the cost of the overdraft facility.
Understanding ETFs, savings plans and compound interest
This guide explains how ETF, savings plan and compound interest calculators fit together in long-term investing.
Property & Housing
Mortgage, purchase costs, rental yield, property tax
Buying real estate – financing, additional costs, rental yield and property tax
The guide combines additional purchase costs, annuity credit, rental yield and property tax reform 2025 to form a unified view of purchase and rental decisions.
Public service
TVöD and TV-L
Understanding TVöD and TV-L – pay groups, levels and annual gross in the public service
The guide explains pay groups, tier logic, TVöD-Bund, TVöD-VKA, TV-L, TV-H tariff areas and the most important special rules such as special annual payments, performance pay and VBL.
Health
BMI, calories, blood alcohol, WHR and ideal weight
Correctly classify BMI, calorie requirement and calorie deficit
The guide explains BMI classification, Mifflin-St-Jeor formula, PAL factors and the concept of a moderate calorie deficit - including limits, common mistakes and cautious recommendations.
Pregnancy & Family
Pregnancy week, ovulation, fertile days, parental leave
Planning a pregnancy in Germany: due date, maternity and parental leave
Due date, maternity protection, parental leave and parental allowance thought through together – with deadlines, examples and the right calculators.
Understanding pregnancy weeks, ovulation and fertile days
This guide explains when pregnancy week, ovulation and fertility window calculators are useful and where their limits are.
Math & School
Rule of three, percentages, grades, conversions, tip
Use the rule of three, percentages and fractions safely
The guide guides you through the rule of three, percentage calculations and fraction calculations, with examples from work, school and everyday life as well as calculation methods for typical special cases.
Work & time
Working time, vacation days, age, dates and business days
Polish nursing staff in Germany: wages, working hours and rights
Minimum wage for nursing care, working time rules, the reality of 24-hour care, the EU recognition of Polish nursing training and the difference between posting and German employment.
Working time, hours and industrial minutes explained
This guide explains when working time, hours and industrial minute calculators are useful and how to read the results.
Cooking & baking
Grams, ml, tablespoons, teaspoons and recipe quantities
Scale pizza dough perfectly - flour, water, salt and yeast in proportion
The guide explains baker's percentages, flour types, hydration, amounts of salt and yeast, cold and warm methods and typical mistakes - with compact tables for 3, 6, 12 and 60 pizzas.
Understanding kitchen conversions for grams, ml, tablespoons and teaspoons
This guide explains why grams and milliliters differ by ingredient, how spoon measures work and how to scale recipe quantities cleanly.
Car & Household
Car, energy, household and practical everyday calculators
Calculate car costs realistically – fuel, electricity, taxes and credit
The guide shows how fuel costs, electricity consumption, vehicle tax, insurance, loss of value and loan installment come together to create a realistic total cost calculation per kilometer.
German car tax (Kfz-Steuer) explained: engine size and CO2
Engine-size and CO2 part, current rates, diesel compared and a note on electric cars – explained clearly.
Audio & acoustics
dB, delay, wavelength, BPM, levels and room modes
Understanding audio calculators for dB, delay, wavelength and BPM
This guide explains when you need dB, delay, wavelength, BPM, room modes, line levels and audio file size calculators in practice.
Frequently asked questions
What are the guides for?
They provide background, classify topics and explain the rules behind the calculators. If you only need a quick number, a calculator is enough; if you want to understand differences, special cases or legal logic, the guide adds the missing context.
Are the guides free?
Yes. All guides are freely available, no registration required. The site is supported by carefully placed advertisements.
Are sources cited?
Yes. At the end of each guide you find the underlying laws, regulations, agency or central-bank sources — with a direct link so you can verify.
In which languages are the guides available?
Native content exists in German, English and Polish; the remaining languages appear machine-translated but are not authoritative there. Polish-relevant topics like housing benefit, care workers and workers in Germany are written natively in Polish.
How often are the guides updated?
On every relevant legal or rule change. The "Last updated" date sits at the top of every guide so you can immediately see how current it is.