Type a table, paste two columns, or start from a sample.
Straight line between neighboring points. The everyday choice.
Find x from y
Inverse linear interpolation
Interpolated y
10
Dots are your table. The line is the interpolant. Diamond marks the query.
Using the surrounding segment
x sits between 0 and 10.
Linear formula
y = y₀ + (x − x₀) / (x₁ − x₀) × (y₁ − y₀)
Plug in
y = 0 + (5 − 0) / (10 − 0) × (20 − 0)
Fraction along the segment
t = 0.5 → y = 10