Sales Forecast Calculator: Next Month's Sales from Past Months
Free tool · Updated October 2, 2026 · By CouponTalk · Reviewed by CouponTalk Expert Reviews on
Your result
Enter your measurements to see your result.
Quick answer
A simple forecast averages your last 3 months; a trend forecast also follows growth. Sales of 420, 450, 470, 500, 520 and 560 units give a 3-month average of 527 and a trend forecast of 581, rising about 27 units a month. For Diwali or Big Billion Days months, add a festive bump based on last year.
How to use this calculator
- Enter monthly unit sales, oldest first. Leave the oldest empty if you have only 3–5 months.
- Pick an adjustment for sale seasons.
- Order stock using the forecast plus safety stock.
Formula
3-month average = average of the last 3 months
Trend forecast = straight-line fit through all months, projected one month ahead
Both are multiplied by the festive adjustment
Forecasts are estimates. Check stock weekly and adjust orders as real sales come in.
Frequently asked questions
Which forecast should I use?
Use the trend forecast when sales grow steadily, and the 3-month average when they go up and down.
How much do sales rise in festive season?
It varies widely by category. Use last year's festive month compared with the month before as your guide.
Should I forecast in units or rupees?
Units, because you order stock in units. Prices change with discounts.
Related calculators
Latest from the blog
View all blogs →
Guide
Which Helmet Is ISI Certified and Safe Under Rs. 2000?
Guide
Best Helmet Brands in India: Vega vs Steelbird vs Studds
Guide
Best 7 Solar Geysers for Indian Homes (300L Buyer’s Guide)
Guide
Top 10 Solar Garden Lights for Indian Homes 2026
Guide
5 Types of Solar Collectors: Flat-Plate, Evacuated Tube, and Concentrating
Guide
Types of Solar Panels in India: Region-Specific Buying Guide
