Assumption builder options

📘 MoM Fixed Change 

MoM stands for Month-over-Month, and Fixed Change means the value increases or decreases by the same amount each month. 

🔍 Plain-English Definition: 
“MoM Fixed Change” means you’re forecasting a line item to go up or down by the same fixed amount every month—like adding £500 to your marketing budget each month, or reducing a cost by £200 monthly. 

🧠 When to Use It in sherloc 

This method is ideal when: 
You expect steady growth or decline in a cost or revenue stream. 
You’re building up a budget gradually (e.g. hiring one new staff member per month). 
You want to model a phased rollout (e.g. increasing ad spend in fixed steps). 

💡 Examples for UK SMEs 

✅ sherloc Tips 

In sherloc, this method is great for non-seasonal, predictable changes. 
Use it when you want to test the impact of gradual increases on cash flow. 
Pair it with MoM % Change if you want to compare fixed vs. percentage-based growth. 

📊 MoM % Change 

🔍 Plain-English Definition: 
“Month-over-Month Percentage Change” means the value increases or decreases by the same percentage every month. 

💡 Example: 
If your revenue is £10,000 in January and you apply a 5% MoM increase, February will be £10,500, March will be £11,025, and so on. 

✅ When to Use: 
You expect compounding growth or decline (e.g. viral product adoption, churn). 
You want to model momentum-based changes (e.g. sales growing 10% monthly). 

🧠 sherloc Tip: 
Use this when forecasting scalable growth—especially for revenue, subscriptions, or variable costs that grow with volume. 

💷 Fixed Amount 

🔍 Plain-English Definition: 
You enter a specific £ amount for each month—no automatic changes. 

💡 Example: 
Rent = £2,000 every month. 
Insurance = £300/month flat. 

✅ When to Use: 
For stable, recurring costs or income. 
When you know the exact amount and it doesn’t change. 

🧠 sherloc Tip: 
Use this for fixed overheads like salaries, rent, or subscriptions. It keeps your base forecast clean and predictable. 

📌 % of Line Item 

🔍 Plain-English Definition: 
This method calculates a value as a percentage of another line item—like saying marketing is 10% of revenue. 

💡 Example: 
Revenue = £20,000 
Marketing = 10% of revenue → £2,000 

✅ When to Use: 
For costs that scale with sales, like transaction fees, commissions, or marketing. 
To keep forecasts proportional and dynamic. 

🧠 sherloc Tip: 
Use this for variable costs tied to performance. It helps you model realistic margins and cash flow. 

📈 Fixed Percentage 

🔍 Plain-English Definition: 
You apply a fixed % rate to a base value—often used for things like VAT, payroll tax, or discounts. 

💡 Example: 
VAT = 20% of taxable sales 
Staff pension = 3% of gross salary 

✅ When to Use: 
For regulatory or contractual rates. 
When the percentage is known and stable. 

🧠 sherloc Tip: 
Use this for taxes, benefits, or discounts. It keeps your forecast compliant and consistent. 

🗓️ Tip: Use “Calendar Period” or “One-Off” to Control Timing 

🔍 What It Means: 
When you choose Fixed % or Fixed Amount, sherloc lets you apply it either: 
Across a calendar period (e.g. Jan–Mar, or Q2 only) 
As a one-off in a specific month 

This gives you precise control over when the cost or income hits your forecast. 

💡 Why It’s Useful: 

Why It Helps: 
Models lumpy or infrequent cash movements accurately—so you don’t overestimate monthly liquidity or understate runway. 

✅ Founder Tip: 
“Use calendar period for costs you want to spread evenly, like insurance or software. Use one-off for big events—like a fundraising round, grant, or major purchase—so your forecast reflects real cash timing and investor expectations.” 

OR

📘 sherloc Forecasting Glossary for Founders 
For UK SMEs using sherloc to forecast cash flow, revenue, and costs—no finance jargon required. 

🔢 Fixed Amount 

Definition: 
Enter a specific £ amount for each month—no automatic changes. 

Example: 
Rent = £2,000/month every month. 

Use When: 
You know the exact value and it doesn’t change. 

Founder Tip: 
Use this for stable costs like rent, salaries, or subscriptions. You can apply it as a one-off (e.g. £5,000 in March) or spread across a calendar period (e.g. £1,200 insurance over Jan–Dec). 

📈 MoM Fixed Change (Month-over-Month Fixed Change) 

Definition: 
The value increases or decreases by the same £ amount each month. 

Example: 
Marketing spend grows by £500/month → Jan: £1,000, Feb: £1,500, Mar: £2,000... 

Use When: 
You’re scaling up or down gradually. 

Founder Tip: 
Great for phased rollouts—like hiring one person per month or slowly increasing ad spend. 

📊 MoM % Change (Month-over-Month Percentage Change) 

Definition: 
The value increases or decreases by the same percentage each month—compounding over time. 

Example: 
Revenue grows 5% monthly → Jan: £10,000, Feb: £10,500, Mar: £11,025... 

Use When: 
You expect momentum-based growth or decline. 

Founder Tip: 
Use this for scalable revenue, subscriptions, or churn. It’s ideal for modeling viral growth or recurring income. 

📌 % of Line Item 

Definition: 
Calculates a value as a percentage of another line item. 

Example: 
Marketing = 10% of revenue → Revenue = £20,000 → Marketing = £2,000 

Use When: 
Costs scale with sales or another driver. 

Founder Tip: 
Perfect for transaction fees, commissions, or marketing budgets tied to performance. Keeps your forecast dynamic and proportional. 

💷 Fixed Percentage 

Definition: 
Applies a fixed % rate to a base value—often used for taxes, benefits, or discounts. 

Example: 
VAT = 20% of taxable sales 
Pension = 3% of gross salary 

Use When: 
The percentage is known and stable. 

Founder Tip: 
Use this for regulatory costs or benefits. You can apply it once or over a calendar period to match timing (e.g. quarterly VAT payments). 

🗓️ Calendar Period vs. One-Off 

Definition: 
Controls when a forecasted item appears. 

Founder Tip: 

“Use calendar period for seasonal or annual costs you want to spread. Use one-off for big purchases or grants that hit once—so your forecast reflects reality.”