Public vs Private School Cost Calculator

Understanding public vs. private school costs

Choosing between public and private school is rarely just an academic decision—it’s also a multi‑year financial commitment. Private school can introduce large, visible expenses (tuition and required fees). Public school may look “free,” but many families still pay meaningful out‑of‑pocket costs (fees, supplies, transportation) and sometimes higher housing or tax burdens tied to living in a specific district.

This calculator compares two scenarios over a chosen number of years:

• Public school total cost: incremental property taxes attributable to the school choice (if any) plus fees/supplies and transportation.
• Private school total cost: tuition plus fees/supplies and transportation, plus an opportunity cost estimate (what tuition money might have earned if invested instead).

What you should enter (field definitions)

Public school costs

• Extra Property Tax Attributable ($/yr): the incremental annual property tax you associate with choosing a particular public school option (for example, paying more to live in a higher‑tax district). If you don’t have a clear incremental number, enter 0.
• School Fees & Supplies ($/yr): annual out‑of‑pocket costs such as activity fees, technology fees, sports, instruments, classroom supplies, uniforms (if any), etc.
• Transportation ($/yr): bus fees, parking, tolls, fuel attributable to school commuting, rideshare, etc.

Private school costs

• Tuition ($/yr): annual tuition you expect to pay out of pocket. If you already know expected scholarships/aid, subtract them first and enter the net tuition.
• Fees & Supplies ($/yr): required fees, books, uniforms, fundraising expectations, technology fees, etc.
• Transportation ($/yr): commuting or private bus costs, similar to the public scenario.

Investment return and time horizon

• Investment Return on Tuition (%): the annual rate of return you assume you could earn if tuition money were invested instead (often a long‑run nominal return assumption). This is used only for the opportunity‑cost estimate.
• Years of School: the number of years you want to compare (e.g., 4 for high school, 8 for middle+high, 13 for K–12).

Formulas used

All inputs are treated as annual amounts. The simplest way to interpret the calculator is: “If these annual costs stayed the same for N years, what would my total outlay be?”

Public school total

Annual public cost is the sum of the three public inputs. Total cost is that annual cost multiplied by years.

Private school total (including opportunity cost)

Direct private cost is tuition + fees + transportation, multiplied by years.

Opportunity cost estimates the future value of investing each year’s tuition instead of paying it. This is modeled as an end‑of‑year series for simplicity (a common approximation):

• Let T be annual tuition.
• Let r be the annual investment return (as a decimal).
• Let n be the number of years.

The future value of an annual series is:

FV = T × (( (1 + r)ⁿ − 1 ) / r)

Then:

Total_private = DirectPrivate + FV

If r is 0%, the opportunity cost is simply T × n (no growth).

How to interpret the results

The results panel shows two totals:

• Public school total: estimated dollars paid/attributed to the public option over the chosen years.
• Private school total: direct private costs plus the modeled investment growth you forgo by paying tuition (opportunity cost).

It’s normal for the “private total” to look much larger once opportunity cost is included—especially over longer time horizons or with higher assumed returns—because the calculator is intentionally showing the tradeoff between paying tuition and investing that cash flow.

Worked example

Assume a 4‑year comparison (e.g., high school):

• Public: extra taxes $1,200/yr, fees/supplies $500/yr, transportation $300/yr
• Private: tuition $18,000/yr, fees/supplies $1,000/yr, transportation $800/yr
• Return r = 5% per year

Public annual cost = 1,200 + 500 + 300 = $2,000 → Public total = 2,000 × 4 = $8,000.

Private direct annual cost = 18,000 + 1,000 + 800 = $19,800 → Direct private = 19,800 × 4 = $79,200.

Opportunity cost of tuition (end‑of‑year series approximation):

FV = 18,000 × (((1.05)⁴ − 1) / 0.05) ≈ 18,000 × 4.3101 ≈ $77,582.

Private total (with opportunity cost) ≈ 79,200 + 77,582 = $156,782.

This doesn’t mean you will literally write a $156k check—rather, it frames private tuition as both a direct expense and a foregone investment opportunity.

Comparison table (what each scenario includes)

Limitations and assumptions (important)

• Annual, level costs: Inputs are treated as annual amounts that stay constant over the entire period. Real costs often rise over time.
• No inflation adjustment: Results are in nominal dollars based on your inputs. If you want an inflation-aware view, you can increase yearly amounts to reflect expected increases.
• Opportunity cost timing: The investment growth is approximated as if the tuition amount were invested once per year. If your real cash flow is monthly, results will differ slightly.
• Taxes are user-defined and incremental: The “extra property tax attributable” field is not total property tax; it’s the portion you believe is tied to the schooling choice. This is inherently subjective.
• Doesn’t include many real-world factors: Financial aid uncertainty, multiple children, childcare changes, tutoring, special education services, home price differences, and the value of time spent commuting are not modeled unless you incorporate them into your annual inputs.
• Not financial or tax advice: This is an estimating tool. For decisions involving tax strategy, housing moves, or large portfolio assumptions, consider consulting a qualified professional.