Logic Model &Theory of Change Builder
Describe your program inputs, activities, and expected changes. Get a professional, funder-ready logic model with assumptions and external factors in seconds.
What Is a Logic Model and Why Do Grant Funders Require It?
A logic model is a one-page visual framework that maps the relationship between a programme's resources (inputs), activities, outputs, and outcomes. It answers the fundamental question funders ask: "If we give you money, what will happen, and how do we know it will work?" Logic models show the logical chain from investment to impact, making your programme theory explicit and testable.
Originally developed in the 1970s for evaluation planning, logic models are now a standard requirement for many grant applications — particularly from government agencies, foundations focused on evidence-based programming, and major institutional funders like the National Lottery Community Fund, Annie E. Casey Foundation, and W.K. Kellogg Foundation. Even when not explicitly required, including a logic model in your application demonstrates strategic thinking and evaluation readiness.
Our free logic model builder guides you through the key components: inputs (what you invest), activities (what you do), outputs (what you produce), short-term outcomes (immediate changes), medium-term outcomes (intermediate changes), and long-term outcomes (ultimate impact). The result is a structured logic model you can include directly in your grant application or programme planning documents.
The Components of a Logic Model
Logic Models vs Theory of Change: What's the Difference?
These terms are often used interchangeably, but there's a meaningful distinction. A logic model is typically a visual, structured table that maps inputs through to outcomes — it's concise, standardised, and often required in a specific format by funders. A Theory of Change is broader: it's a narrative explanation of how and why you believe change happens, including your assumptions about causal mechanisms and the conditions required for success.
Think of a Theory of Change as the story and the logic model as the diagram. Strong grant applications often include both: the Theory of Change explains the "why" behind your approach, while the logic model maps the "what" in a structured, evaluable format. Together they show funders that you've thought rigorously about how your work produces change.
If a funder asks specifically for a logic model, use this tool. If they ask for a Theory of Change, use our Theory of Change builder. If they want both — as many larger funders do — both tools work together.
Frequently Asked Questions
Do I need a logic model for every grant application?
Not always, but having one ready is good practice even when it's not required. Many medium and larger funders require a logic model or similar programme theory framework. For smaller grants (under £10,000), it may not be asked for, but the thinking behind a logic model will strengthen your answers to standard questions about activities, outputs, and outcomes. Consider your logic model as a planning tool as much as a compliance document.
How detailed should a logic model be?
A logic model should be concise enough to fit on one page while capturing the essential logic of your programme. Avoid listing every minor activity or output — focus on the most significant ones. If your programme has multiple distinct components, you may need separate logic models for each strand or a higher-level model that covers the programme as a whole. The goal is clarity, not comprehensiveness.
What's the difference between outputs and outcomes?
Outputs are the direct, countable products of your activities — the number of sessions delivered, participants reached, meals served, or resources produced. Outcomes are the changes that result from those outputs — improvements in wellbeing, new skills developed, changed behaviours, or reduced isolation. Many inexperienced grant writers describe outputs when funders are asking for outcomes. If you can count it directly and immediately, it's probably an output. If it represents a change in someone's knowledge, behaviour, or circumstances, it's an outcome.
How do I know if my logic model is realistic?
Sense-check your logic model by asking: Are the activities sufficient to produce the stated outputs? Are the outputs sufficient to lead to the short-term outcomes? Is the causal chain between activities and long-term outcomes credible, or are there too many assumptions required? If there are large logical jumps between steps, your model may be too ambitious or may need to be explicit about the intermediary factors required. Peer review from colleagues outside your programme can surface assumptions you've taken for granted.
Can I use a logic model for internal planning, not just grant applications?
Absolutely — and many practitioners argue this is a logic model's most valuable use. A well-constructed logic model aligns your team around what you're trying to achieve and how. It surfaces disagreements about programme theory before they become operational problems. It guides monitoring and evaluation design. And it helps you make decisions about what to continue, change, or stop based on which links in the chain are and aren't working as expected.