To calculate sum of specific column of dataframe you can use **rowSums()** function in R.

The following method shows how you can do it with syntax.

**Method 1: Use rowSums() Function**

```
rowSums(df[ , c(columns to sum)])
```

The following example shows how to use **rowSums()** function in R.

## Use rowSums() to Calculate Sum of Specific Columns

Let’s see how we can calculate sum of specific column of data frame:

```
# Create data frame
df <- data.frame(Machine_name=c("A","B","C","D","E","F"),
Pressure=c(78.2, 71.7, 80.21, 83.12, 82.56, 79.50),
Temperature=c(31, 35, 36, 36, 38, 32),
Status=c(TRUE,TRUE,FALSE,FALSE,FALSE,TRUE))
# Calculate sum of specific columns
sum<-rowSums(df[ , c("Pressure","Temperature")])
# Print sum
print(sum)
```

Output:

```
[1] 109.20 106.70 116.21 119.12 120.56 111.50
```

As the output shows sum of “Pressure” and “Temperature” column of dataframe.