Math Technique
T-Bar (IRV) Method: Real Estate Exam Math Explained
The T-Bar method (also called IRV — Income, Rate, Value) is a visual shortcut for solving any of the three variables when given the other two. Income on top, Rate × Value on the bottom. Cover the variable you want, and the formula appears.
The T-Bar Visualization
Draw a T. Put I (Income) on top. Put R (Rate) × V (Value) on the bottom. To find any variable, cover it: I = R × V; V = I ÷ R; R = I ÷ V.
This works for any cap-rate-style problem (cap rate, GRM, etc.) — and it's the fastest mental model for income property questions.
Three Worked Examples
Question 1
Income = $100,000. Rate = 8%. What's the Value?
Cover V. V = I ÷ R = $100,000 ÷ 0.08 = $1,250,000.
Question 2
Value = $750,000. Rate = 7.5%. What's the Income (NOI)?
Cover I. I = R × V = 0.075 × $750,000 = $56,250.
Question 3
Income = $120,000. Value = $1,500,000. What's the Rate?
Cover R. R = I ÷ V = $120,000 ÷ $1,500,000 = 0.08 or 8%.
When to Use T-Bar
Cap rate problems (most common use)
Gross Rent Multiplier problems (treat GRM as 'rate')
Any problem with three related variables where you have two
Commission problems (T-Bar with Total Commission, Rate, Sale Price)
Any percentage relationship: Part = Rate × Whole
Practice T-Bar Problems
Drill 20+ income/rate/value problems on the math page.
Related Walkthroughs
T-Bar FAQ
Why is T-Bar useful?
It eliminates memorizing three separate formulas. One visual replaces the formulas for value, rate, and income.
Does T-Bar work for percentage problems?
Yes. Any 'Part = Rate × Whole' relationship can be visualized as T-Bar with Part on top, Rate × Whole on bottom.
Can I use T-Bar for commission?
Yes. Total Commission on top, Rate × Sale Price on bottom. Cover what you need to find.