# Speeds and Feeds Calculator

URL: https://speedycalculator.com/calculators/physics/speeds-and-feeds/
Last updated: 2026-10-30

> The speeds and feeds calculator finds the spindle speed and feed rate for turning, milling, drilling and reaming from the workpiece material, cutting tool and diameter – or from a manual cutting speed and chip load.

## Inputs

- Cutting speed from
- Workpiece material
- Tool material
- Cutting speed (SFM)
- Operation
- Tool (or work) diameter (in, mm, cm, ft, m)
- Number of teeth / flutes
- Chip load per tooth (in)

## Results

- Cutting speed used
- In m/min
- Spindle speed
- Feed rate
- Feed rate (metric)

## Formula

```
RPM = (SFM × 12) / (π × D in) ≈ 3.82·SFM/D · Feed (in/min) = RPM × teeth × chip load
```

## Explanation

Cutting at the right speed keeps tools sharp and finishes smooth. Each material has a recommended surface speed: soft aluminium can be cut very fast, stainless steel and titanium slowly. Carbide tools allow roughly three times the speed of high-speed steel.

### How to use the Speeds and Feeds Calculator

- **Cutting speed from**
- **Workpiece material**
- **Tool material**
- **Cutting speed (SFM)**
- **Operation**
- **Tool (or work) diameter**
- **Number of teeth / flutes**
- **Chip load per tooth (in)**

Results update as you type, every field has its own unit menu, and everything is calculated in your browser.

### How it works

Choose preset (material and tool) or manual cutting speed, the operation, and enter the tool or work diameter, number of teeth (flutes) and chip load per tooth. Values are typical starting points – check your tool maker's data.

### Inputs explained

FieldWhat to enterCutting speed fromChoose one: Material preset, Manual valueWorkpiece materialChoose one: Aluminium, Brass, Bronze, Grey cast iron …Tool materialChoose one: High-speed steel (HSS), CarbideCutting speed (SFM)A numberOperationChoose one: Turning / end milling, Face / slab milling, Drilling, Counterboring …Tool (or work) diameterUnits: in, mm, cm, ft, mNumber of teeth / flutesA numberChip load per tooth (in)A number

### What each result means

- **In m/min** = [Cutting speed used]×0.3048
- **Spindle speed** = [Cutting speed used]×12÷(pi×[Tool (or work) diameter]÷0.0254)
- **Feed rate** = [Spindle speed]×[Number of teeth ÷ flutes]×[Chip load per tooth (in)]
- **Feed rate (metric)** = [Spindle speed]×[Number of teeth ÷ flutes]×[Chip load per tooth (in)]×25.4

### Example values

How the main result changes when **Cutting speed** changes and everything else stays at the example values above:

Cutting speed (SFM)Spindle speed (rpm)5076475764100764125764150764200764

## Worked example

Inputs — Cutting speed from: Material preset; Workpiece material: Mild steel (1018); Tool material: High-speed steel (HSS); Operation: Turning / end milling; Tool (or work) diameter: 0.5 in; Number of teeth / flutes: 2; Chip load per tooth (in): 0.002.

Results — Cutting speed used = 100 SFM; In m/min = 30.5 m/min; **Spindle speed = 764 rpm**; Feed rate = 3.06 in/min; Feed rate (metric) = 77.6 mm/min.

## Key terms

- **Chip load**: Thickness of material removed by each tooth.

## FAQ

**What is SFM?**
Surface feet per minute – the speed of the cutting edge past the material.

**Why does diameter change the rpm?**
Smaller tools must spin faster for the same edge speed.

**What chip load should I use?**
Tool makers list it by diameter and material; 0.001–0.005 in is common for small end mills.

**Why is reaming slower?**
Lower speed gives better hole finish and tool life.


## Sources

- [The Engineering ToolBox](https://www.engineeringtoolbox.com/)
- [Machinery's Handbook (Industrial Press)](https://new.industrialpress.com/machinery-s-handbook-31st-edition.html)