Sum of Linear Number Sequence

Initial value
Difference
Periods
Final value
Sum

This calculator deals with a linear number sequence - a set of values where every consecutive one differs by the same amount from the previous one. An example would be 20, 23, 26, 29 - it's a sequence of 4 numbers, with 20 as the initial value, 3 as the difference between successive figures, 29 as the final value and 98 as the sum of all numbers.

A practical example.

We're selling photo storage in the cloud. Customers pay us an amount of money that's directly proportional to the amount of data that they upload - $1 per 1 Gigabyte. Alice initially uploads 5GB of family photos and then adds 2GB per month. We want to know how much she stores after a year and how much her business is worth to us during that time. Below you'll find a table with all the values and a pre-filled calculator widget.

MonthPaymentSum
1 5 5
2 7 12
3 9 21
4 11 32
5 13 45
6 15 60
7 17 77
8 19 96
9 21 117
10 23 140
11 25 165
12 27 192