Speedy Calculator

MPS Calculator – Marginal Propensity to Save

Finance Updated October 25, 2026

Quick answer

The MPS calculator works out the marginal propensity to save – the share of each extra dollar of income that is saved – and the matching MPC and multiplier.

$
$
Marginal propensity to save
—
Marginal propensity to consume
—
Multiplier
—

A higher MPS means more of each extra dollar is saved rather than spent, which reduces the multiplier effect of fiscal policy in the short run but supports investment in the long run.

How to use the MPS Calculator – Marginal Propensity to Save

  1. Change in saving
  2. Change in disposable income

Results update as you type, and every field accepts the units shown in its menu.

How it works

Enter the change in saving and the change in disposable income.

Tips

  • Use real (inflation-adjusted) figures to compare across years.
  • Check whether data are seasonally adjusted.
  • Use the same currency and base year throughout.
  • Economic models simplify reality – treat results as illustrations, not forecasts.

Common mistakes to avoid

  • Mixing nominal and real values.
  • Comparing percentage changes with percentage-point changes.
  • Treating correlations as causes.

Inputs explained

Field What to enter
Change in saving Amount in your currency
Change in disposable income Amount in your currency

What each result means

  • Marginal propensity to save = [Change in saving]÷[Change in disposable income]
  • Marginal propensity to consume = 1 – [Change in saving]÷[Change in disposable income]
  • Multiplier = [Change in disposable income]÷[Change in saving]

Example values

How the main result changes when Change in saving changes and everything else stays at the example values above:

Change in saving Marginal propensity to save
100 0.1
150 0.15
200 0.2
250 0.25
300 0.3
400 0.4

Formula

MPS = change in saving ÷ change in incomeMPC = 1 − MPSMultiplier = 1 ÷ MPS

Worked example

Inputs — Change in saving: $200; Change in disposable income: $1,000.
Results — Marginal propensity to save = 0.2; Marginal propensity to consume = 0.8; Multiplier = 5.

Frequently asked questions

What is MPS?

The fraction of additional income saved.

How do MPS and MPC relate?

MPS + MPC = 1.

What is the multiplier in terms of MPS?

1 ÷ MPS.

What formula does the MPS Calculator – Marginal Propensity to Save use?

MPS = change in saving ÷ change in income.

Cite this calculator

Speedy Calculator. (2026). MPS Calculator – Marginal Propensity to Save. Speedy Calculator. https://speedycalculator.com/calculators/finance/mps/