A Streamlit calculator that projects how a Dutch DUO student debt (SF35 rules: loans from September 2015 onward) develops — through the years you're borrowing (one or many studies, or a known current balance if you've already graduated), the 2-year grace period, and up to 35 years of repayment — and compares DUO's income-tested minimum payment (draagkracht) against paying more and investing the difference instead. Includes an approximate net-income estimate. Income, the draagkracht threshold, and the investment return are modeled in real (inflation-adjusted) terms; the interest rate is DUO's published nominal rate, applied as-is — mixing a nominal rate with everything else in real terms modestly overstates real balance growth (and so overstates forgiveness).
No accounts, no stored data: every result is computed fresh from whatever you enter in the sidebar.
python3 -m venv .venv
.venv/bin/pip install -r requirements.txt
.venv/bin/streamlit run app.py.venv/bin/pytest -v- Push this repo to GitHub.
- Go to https://share.streamlit.io and sign in with your GitHub account.
- Click "New app", pick this repo/branch, set the main file path to
app.py. - Deploy. The app rebuilds automatically on every push to the branch you picked.
The free tier sleeps the app after a period of inactivity; the next visitor triggers a ~30 second wake-up.