US debt interactive VIN diagram. You are welcome!

Play with the interactive debt model.

And here is our debt relative to GDP and more.

Cost of cutting SNAP Diagram

• User Inputs: Sliders or input fields for key variables:
• Initial Debt Amount – e.g., default to $3 trillion (for a specific new debt analysis) or $37 trillion (for total debt), but allow any value.
• Interest Rate – allow the user to choose a constant rate or even a custom interest rate path (e.g., 5% for first 5 years, 3% thereafter). Possibly include presets for “low/med/high” scenarios.
• Repayment Timeline – choose the number of years (or toggle between interest-only vs. full amortization). For example, a slider from 1 to 50 years for payoff period, or a toggle for “interest only, no principal repayment” to see how debt grows if you never pay principal.
• Inflation Rate – to incorporate an inflation assumption. This could be used to display results in real terms vs nominal, or to adjust the interest rate if modeling real vs nominal. For instance, user could set inflation at 2% and see the real value of debt over time.
• Refinancing Options – possibly an advanced setting to allow interest rate changes over time. For example, input a future interest rate drop or increase at a certain year, or an option to use a built-in interest rate projection (like CBO’s forecast curve) instead of a constant rate.
• Outputs and Visualization: Once the user sets the inputs, the tool would display dynamic charts/graphs such as:
• Debt Balance Over Time: A line chart showing how the principal amount would decline (if being repaid) or increase (if interest not fully covered) year by year. In a full repayment scenario, this line goes to zero by the chosen timeline; in an interest-only or deficit scenario, it might climb.
• Annual Interest Payments: A bar or line chart showing interest paid each year. If rates are constant and it’s amortized, this might start high and decrease as principal drops. If interest rates change, the graph would reflect that (e.g., spike when refinancing at higher rate).
• Cumulative Interest Paid: Perhaps a secondary line that accumulates the total interest paid up to each point in time. By the end of the timeline, this reaches the total interest cost. This could be represented in a stacked area chart together with principal repayments to show the composition of total payments.
• Total Repayment Cost: A headline number (and possibly a pie chart) showing principal vs. total interest paid. For example, it might say “Total Paid: $5.5T, of which $2.5T is interest” for a given scenario. This helps users see the long-term cost of interest.
• Real vs Nominal Comparison: If inflation is provided, the tool can show the debt in real terms (today’s dollars) vs nominal. For instance, it might show that a $37T debt in 30 years is only $20T in today’s dollars if inflation averages 3%. It could also show the real value of cumulative interest. This feature underscores inflation’s effect.
• Interactive “What-If” Exploration: The user can instantly see how changing an assumption alters the outcome. For example:
• Slide interest from 3% to 6% and watch the total interest bar jump dramatically in response.
• Extend the timeline from 10 to 30 years and watch the annual payment line drop but the cumulative interest grow on the summary.
• Increase inflation and watch the real debt line fall faster (while nominal stays same) – illustrating debt erosion by inflation.
• Apply a future interest rate shock (maybe a checkbox like “simulate rate spike in Year 5”) and see the impact on interest thereafter.
• Scenario Presets and Comparisons: The tool could include preset buttons for scenarios discussed in this report (e.g., “Low rate 3%, 10-year” vs “High rate 6%, 30-year”) and allow toggling between them or showing multiple scenarios on the same graph. For instance, it could overlay two lines for debt payoff: one for the low-rate scenario and one for high-rate, to visualize how much more slowly the debt declines in the high-rate case (because payments go more to interest). Or overlay interest payment curves for different scenarios. This would effectively function as a sandbox for fiscal scenarios, in line with the ranges we analyzed.