Family Finance, Explained
Calculators and guides for parents and teens. From first allowance to first paycheck to college savings — the math made clear.
For parents
Plan age-appropriate allowances. Model long-term college savings with real tax benefits. Understand what your teen’s paycheck looks like after withholding. Evaluate whether that first car is financially realistic for your family.
For teens
See what your first paycheck actually looks like after taxes. Understand what happens when you save even small amounts consistently. Figure out the real cost of a car — not just the sticker price, but insurance, gas, and maintenance.
Calculators
Compound Interest Visualizer
See how small, consistent savings grow over years and decades. Adjust rate, contributions, and time.
Open calculator →Allowance Calculator
Age-appropriate allowance ranges based on published norms, adjusted for your family and region.
Open calculator →Teen Paycheck Calculator
Enter gross pay, see what comes home after federal and state taxes, Social Security, and Medicare.
Open calculator →529 College Savings Projector
Model contributions, growth, and state tax benefits for 529 education savings plans.
Open calculator →First-Car Calculator
Total cost of ownership: purchase price, insurance, gas, maintenance, and registration by state.
Open calculator →Guides
Our Editorial Approach
Every calculator on this site uses publicly available data from authoritative sources: IRS.gov for federal tax brackets, state revenue departments for state taxes, SEC.gov and investor.gov for investment return context. Data is year-tagged in our source files so you always know which tax year or survey year a calculation reflects.
We do not include affiliate links inside calculator results. The numbers you see come from the math and the data, not from a partnership. If we reference a financial product (like a 529 plan), we link to the state’s official program page, not to a brokerage.
Our methodology is public. Every assumption, data source, and limitation is documented on the methodology page. If something is approximate, we say so. If a calculation has known limitations, we note them inline. Transparency is not optional for a site that handles financial topics.
Frequently Asked Questions
Is this financial advice?
No. This site provides educational calculators and informational content. We are not licensed financial advisors, tax professionals, or fiduciaries. The tools estimate outcomes based on publicly available data and user-provided inputs. They are starting points for learning and planning, not substitutes for individual professional advice.
How current is this data?
All data is year-tagged in our source files and methodology page. Federal tax brackets are updated annually when the IRS publishes new tables (typically October-November for the following year). State tax data is updated on the same cycle. Allowance norms and insurance data are updated when new survey data becomes available. Each calculator notes the data year it uses.
Who built this?
Oddlogix LLC, a software consulting and SaaS company based in Rock Hill, South Carolina. The founder has personal experience managing multi-source retirement income from federal service and builds these tools to fill gaps in the family finance space. More detail on the About page.
Are my inputs saved anywhere?
No. All calculations run entirely in your browser. Your numbers (salary, savings, age) are stored only in the URL hash on your device so you can bookmark or share results. We do not transmit, store, or have access to anything you type into a calculator.
Why Parent mode and Teen mode?
Parents and teens look at the same numbers differently. A parent planning college savings needs tax implications and long-term projections. A teen looking at their first paycheck needs to understand what each deduction means and what they can actually spend. The mode toggle adjusts language, defaults, and result framing — not the math. The calculations are identical.
Can I share a calculation with my family?
Yes. Every calculator stores its inputs in the page URL. Copy the URL from your browser and send it to anyone — they will see exactly the same inputs and results. This works for texting a paycheck breakdown to your teen or emailing a 529 projection to your partner.
How is this site funded?
Display advertising via Google AdSense. There are no subscriptions, premium features, or affiliate links inside calculator results. We chose advertising because it keeps every tool free and removes any incentive to steer you toward a product. If the ads bother you, the calculators work fine with an ad blocker.