How I Built a Car Budget Calculator and Started My SEO Journey

By Emirhan Ozsoy

I’ve been a full-time software engineer for a while, but like many folks in tech, I wanted to start something on my own—a side project that could generate passive income and maybe turn into something bigger down the road. That’s how budgetforcars.com was born: a simple Car Budget Calculator built around the 20/4/10 rule and some basic guides.

In this post, I’ll walk you through how I built the site using React (MUI) and deployed it on Google Cloud Run, as well as the steps I’m taking to market it. I’ve had some short-term wins but also learned a few lessons along the way, especially about SEO and content strategy.

The Idea: A Car Budget Calculator

I noticed friends and family struggling to figure out how much car they could afford without blowing their budget. The 20/4/10 rule—where you put down 20% on a car, pay it off in 4 years or less, and keep total transportation costs under 10% of your income—seemed like a popular guideline.

Why a Calculator?

A free, interactive tool is easy to share.
Tools often attract backlinks naturally if they solve a specific problem (like budgeting).
It’s straightforward from an engineering perspective: gather inputs (income, down payment, interest rate, loan term), run calculations, display results.

After coding up the first version in React, I deployed the site on Google Cloud Run. Nice and simple.

Step 1: SEO and Content Foundations

My Biggest Surprise? Realizing that just having a cool tool isn’t enough. Google and users want content—guides, references, details. Without it, you’re stuck ranking in oblivion.

What I Added Next:

Three Blog Posts to complement the calculator:
- Understanding the 20/4/10 Rule
- Car Buying Tips for First-Time Buyers
- Best Affordable Cars Under $25,000
Basic On-Page SEO:
- Page titles with keywords like “Car Budget Calculator”
- Helpful meta descriptions
- Internal links from each blog post back to the calculator page

Step 2: Performance and Indexing

Performance:

I ran a quick PageSpeed Insights check. Both mobile and desktop ended up scoring above 90, which is a good indicator. React on Cloud Run can be performant if you minimize and compress assets correctly.

Indexing Hurdles:

My site is brand new, so impressions in Google Search Console hovered near zero.
Over time, some pages started to get a handful of impressions, and the domain rating was about 29.
I added location-based and income-based dynamic pages to the sitemap, hoping they’d rank for “Car Budget in [State]” or “Car Budget with $X Salary.”
However, these template-like pages didn’t offer unique content yet, so many remain unindexed. Lesson learned: Google wants original, valuable content. If you generate lots of pages with near-identical text, they’re less likely to get indexed.

Step 3: Marketing in Bite-Sized Chunks

I have a day job, so I can’t spend all day marketing. I set aside an hour each day (or every couple of days) to do something small but meaningful:

Reddit Personal Finance Subreddit
- I answered questions about budgeting, linking to my calculator if it was genuinely relevant. Over a week, I saw a slow uptick in visitors—around 15 new users—and impressions climbed to ~40–50 in Search Console.
Twitter (X)
- I posted a short tweet introducing my calculator and tagging a personal finance influencer in a follow-up comment. Got a little engagement, a few visits, but not a massive spike.
Guest Posts & Link Building (planned)
- Next, I want to write a guest post for a personal finance blog, hopefully securing a backlink to budgetforcars.com. Building domain authority is key to ranking well.
Product Hunt (Later)
- Launches on Product Hunt do best if you plan them out and gather some early upvotes from your network. I decided to delay a PH launch until I’m ready with a polished pitch and have a more robust offering—maybe an expanded calculator with monthly cost breakdowns, insurance estimates, etc.
Hacker News “Show HN”
- Another potential route. Hacker News loves seeing interesting side projects with a story behind them. But again, I’ll do it when I can invest the time to interact with comments.

Key Lessons Learned So Far

Content Depth Matters: A single-page calculator won’t get much organic traffic. Supplement with blog posts or guides that add real value.
Small, Consistent Marketing Steps: Rather than massive PR campaigns, I found success focusing on one community at a time (e.g., Reddit) for a short burst of consistent engagement.
Be Patient with Indexing: Google might take weeks (or longer) to fully index new pages, especially if they’re thin or very similar. If you generate a bunch of location or income pages, add more context to each.
Analytics and Key Events: Setting up Google Analytics (GA4) event tracking helped me see which pages people visited and how often they used the calculator. Data-driven decisions over guesswork.

What’s Next?

Enrich Those Location/Income Pages: I’ll add specific paragraphs about local taxes or cost-of-living considerations for each state. For income-based pages, maybe some quick tips on budgeting strategies for each salary bracket. This should help differentiate them so Google sees unique value.
Build Out the Content Hub: Maybe 2-3 more blog posts or resource pages addressing questions like “Is leasing vs. buying better for your budget?” or “How to factor insurance and maintenance costs into your 20/4/10 rule.”
Gradual Link Building: Guest posts, press release on a small aggregator, or pitching to personal finance newsletters might bring in more authority.

Wrapping Up

Budgetforcars.com is still in the early days, but the journey so far shows how crucial content, SEO fundamentals, and small marketing steps are to growing a new project. If you have a side hustle or a product you want to share, don’t get discouraged by small daily impression dips—that’s normal. Just keep iterating on your content, improving the user experience, and finding relevant communities to engage with.

Thanks for reading! If you have any questions about building an SEO-friendly calculator site in React or want to swap tips on marketing side projects, drop a comment below!

About Me

I’m a full-time software engineer with a penchant for side projects and passive income experiments. You can follow my journey on Hashnode or find me on Twitter (X) at Emirhan Özsoy.