# MPS Calculator – Marginal Propensity to Save

URL: https://speedycalculator.com/calculators/finance/mps/
Last updated: 2026-10-25

> 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.

## Inputs

- Change in saving
- Change in disposable income

## Results

- Marginal propensity to save
- Marginal propensity to consume
- Multiplier

## Formula

```
MPS = change in saving ÷ change in income
MPC = 1 − MPS
Multiplier = 1 ÷ MPS
```

## Explanation

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

- **Change in saving**
- **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

FieldWhat to enterChange in savingAmount in your currencyChange in disposable incomeAmount 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 savingMarginal propensity to save1000.11500.152000.22500.253000.34000.4

## 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.

## FAQ

**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.