In Ashland, we say the foundation is everything. A house settles, but a wall with proper prep stands for generations. The same is true for mortgages. The advertised rate is a lie of omission—it tells you the price of the first brick, but not the weight of the mortar between them.
This tool cuts through the marketing. Input the nominal rate, the compounding frequency, and watch the true cost reveal itself. Built for first-time buyers in Union County who deserve to know what they're really signing.
The Formula
Where:
• APY = Annual Percentage Yield (true effective rate)
• i_nom = Nominal annual interest rate (as decimal)
• N = Compounding periods per year
Why this matters: A 6% nominal rate compounded monthly (N=12) yields 6.17% annually. That 0.17% difference on a $300k mortgage is $510/year—or $18,360 over 30 years. The frequency is the silent partner in your debt.
Worked Example
Nominal rate: 6.5%, Monthly compounding (N=12)
Step 1: Convert percent to decimal → 0.065 Step 2: Divide by N → 0.065 ÷ 12 = 0.00541667 Step 3: Add 1 → 1.00541667 Step 4: Raise to power N → 1.00541667^12 = 1.06697 Step 5: Subtract 1 → 0.06697 = 6.697%
Result: 6.70% APY vs. 6.50% nominal. True cost revealed.
All calculations performed client-side. No data leaves your browser.
A Note from Ashland
I've spent twenty years mixing pigments, scraping surfaces, and teaching communities that beauty requires rigor. This calculator is my way of extending that philosophy beyond the wall. Just as you wouldn't trust a finish without knowing the primer's pH, don't trust a loan without seeing its true yield.
To every first-time buyer in Union County: the math is yours to wield. Sign nothing until you've calculated the cost.