What inputs does the Sales Forecast Calculator need?

It takes 6 inputs: starting_mrr (default 80000), monthly_growth_percent (default 5), pipeline_conversion_percent (default 22), avg_deal_size (default 1200), new_opportunities_per_month (default 40), months (default 12). Outputs returned: projectedMrr, cumulativeRevenue, monthlyPipelineContribution, growthRate.

Can I verify the Sales Forecast Calculator with a worked example?

Yes. With starting_mrr = $10,000, monthly_growth_percent = 4, pipeline_conversion_percent = 20, avg_deal_size = $500, new_opportunities_per_month = 30, months = 12. the tool returns monthlyPipelineContribution = $3,000, projectedMrr ≈ $61,087.74, cumulativeRevenue ≈ $428,281.20.

Does the Sales Forecast Calculator bundle any external benchmark data?

No. It runs standard arithmetic on the values you enter; no external benchmark dataset is bundled. Industry references, where relevant, are cited on the adjacent tools' methodology pages.

What can the Sales Forecast Calculator not tell me?

Known limitations: Deterministic, not probabilistic. A ±20% range on any input cascades across the horizon; the tool does not surface that uncertainty. No churn or contraction term — this is a gross-additions forecast, so it overstates net MRR for products with meaningful churn. No seasonality layer. E-commerce and consumer products with Q4 spikes will be off by a meaningful margin.

Methodology: Sales Forecast Calculator

1. Scope

Projects MRR and cumulative revenue over a fixed horizon using deterministic growth, conversion, and pipeline assumptions. It is not a probabilistic forecast and does not quantify forecast error.

2. Inputs and outputs

Inputs

starting_mrr number (currency) default: 80000
monthly_growth_percent percent default: 5

Organic month-over-month MRR growth.
pipeline_conversion_percent percent default: 22

Share of new opportunities that close.
avg_deal_size number (currency) default: 1200
new_opportunities_per_month number default: 40
months number default: 12

Forecast horizon, 1–60.

Outputs

projectedMrr

MRR at the end of the chosen horizon (primary value).
cumulativeRevenue

Sum of MRR across every month of the horizon.
monthlyPipelineContribution

new_opportunities_per_month × conversion × avg_deal_size (constant each month).
growthRate

Echoes the monthly organic growth percent.

Engine source: src/lib/sales-forecast-calculator/engine.ts

3. Formula / scoring logic

for m = 1..months:
  organic  = mrr_{m-1} * (monthly_growth_percent / 100)
  pipeline = new_opportunities_per_month * (pipeline_conversion_percent / 100) * avg_deal_size
  mrr_m    = mrr_{m-1} + organic + pipeline
  cumulative_revenue += mrr_m

4. Assumptions

Organic growth compounds on the prior month's MRR; pipeline adds a constant dollar amount each month. There is no churn term.
Opportunity volume, conversion, and deal size are constant across the horizon. Ramp periods require running the tool in segments.
The horizon is clamped to 1–60 months.

5. Data sources

This tool relies on user inputs and standard arithmetic; no external benchmark data is bundled. When a question depends on an industry reference (for example, typical churn rates or hourly-wage medians), the linked adjacent tools cite their primary sources on their own methodology pages.

6. Known limitations

Deterministic, not probabilistic. A ±20% range on any input cascades across the horizon; the tool does not surface that uncertainty.
No churn or contraction term — this is a gross-additions forecast, so it overstates net MRR for products with meaningful churn.
No seasonality layer. E-commerce and consumer products with Q4 spikes will be off by a meaningful margin.

7. Reproducibility

Input
starting_mrr = $10,000, monthly_growth_percent = 4, pipeline_conversion_percent = 20, avg_deal_size = $500, new_opportunities_per_month = 30, months = 12.

Expected output
monthlyPipelineContribution = $3,000, projectedMrr ≈ $61,087.74, cumulativeRevenue ≈ $428,281.20.

8. Change log

2026-04-24 methodology page first published.

Worked example

Run live against the same engine this site ships (/engines/sales-forecast-calculator.js). The inputs and outputs below are recomputed on every build and independently re-verified in CI — they are never hand-authored.

Input

tool: sales_forecast
starting_mrr: 80000
monthly_growth_percent: 5
pipeline_conversion_percent: 22
avg_deal_size: 1200
new_opportunities_per_month: 40
months: 12

Output

primaryLabel: Projected MRR at horizon
primaryValue: 311753.36
primaryFormat: currency
summary: Combines organic growth with conversion-weighted pipeline additions each month.
metrics[0].label: Cumulative forecast revenue
metrics[0].value: 2332420.6
metrics[0].format: currency
metrics[1].label: Monthly pipeline contribution
metrics[1].value: 10560
metrics[1].format: currency
metrics[2].label: Growth rate
metrics[2].value: 5
metrics[2].format: percent
metrics[3].label: Forecast horizon
metrics[3].value: 12
metrics[3].format: months
assumptionsEcho.starting_mrr: 80000
assumptionsEcho.monthly_growth_percent: 5
assumptionsEcho.pipeline_conversion_percent: 22
assumptionsEcho.avg_deal_size: 1200
assumptionsEcho.new_opportunities_per_month: 40
assumptionsEcho.months: 12

Frequently asked questions

What does the Sales Forecast Calculator calculate?: Projects MRR and cumulative revenue over a fixed horizon using deterministic growth, conversion, and pipeline assumptions. It is not a probabilistic forecast and does not quantify forecast error.
What inputs does the Sales Forecast Calculator need?: It takes 6 inputs: starting_mrr (default 80000), monthly_growth_percent (default 5), pipeline_conversion_percent (default 22), avg_deal_size (default 1200), new_opportunities_per_month (default 40), months (default 12). Outputs returned: projectedMrr, cumulativeRevenue, monthlyPipelineContribution, growthRate.
What formula does the Sales Forecast Calculator use?: The exact computation is: for m = 1..months:; organic = mrr_{m-1} * (monthly_growth_percent / 100); pipeline = new_opportunities_per_month * (pipeline_conversion_percent / 100) * avg_deal_size; mrr_m = mrr_{m-1} + organic + pipeline; cumulative_revenue += mrr_m
Can I verify the Sales Forecast Calculator with a worked example?: Yes. With starting_mrr = $10,000, monthly_growth_percent = 4, pipeline_conversion_percent = 20, avg_deal_size = $500, new_opportunities_per_month = 30, months = 12. the tool returns monthlyPipelineContribution = $3,000, projectedMrr ≈ $61,087.74, cumulativeRevenue ≈ $428,281.20.
Does the Sales Forecast Calculator bundle any external benchmark data?: No. It runs standard arithmetic on the values you enter; no external benchmark dataset is bundled. Industry references, where relevant, are cited on the adjacent tools' methodology pages.
What can the Sales Forecast Calculator not tell me?: Known limitations: Deterministic, not probabilistic. A ±20% range on any input cascades across the horizon; the tool does not surface that uncertainty. No churn or contraction term — this is a gross-additions forecast, so it overstates net MRR for products with meaningful churn. No seasonality layer. E-commerce and consumer products with Q4 spikes will be off by a meaningful margin.